cPanel Glossary From (A) to (H)

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Table of contents
A
A (Address) Entry
Absolute Domain Name
Access Control List (ACL)
Account
Account Enhancements
Account Suspension
Account-Level Filter
Addon Domain
Addons (cPAddons)
Aliases
AlmaLinux OS
Analog
Ancestor Domain Control Validation
Anonymous FTP
Apache®
Apache Handler
Apache SpamAssassin™
API Token
Application Key (app_key)
Application Programming Interface (API)
atd
Authenticated Received Chain (ARC)
Authentication
Authoritative Nameserver
AutoConfig
Autoresponder
AutoSSL
AWStats (Advanced Web Statistics)
B
Backscatter
Backup
Bandwidth
Bayes Testing (Bayesian Spam Filtering)
Berkeley Internet Name Domain (BIND)
Blackhole (Black Hole)
Blacklist
Blocker
Bounce Message
BoxTrapper
Branding
Brute Force Attack
Bug
Build
C
.crt File
Cache
Cascading Style Sheets (CSS)
Catch-All Address (Domain Default Address)
Certificate
Certificate Authority (CA)
Certificate Authority Authorization Record (CAA)
Certificate Authority Bundle (CA Bundle)
Certificate Signing Request (CSR)
Chain Of Trust
Change Log
Character Set
Child Node
Classless Inter-Domain Routing (CIDR)
Client
CloudLinux™
Cluster
Collection
Command Line Interface (CLI)
Common Gateway Interface (CGI)
Common Vulnerabilities and Exposures (CVE® ) System
Compiler
Comprehensive Perl Archive Network (CPAN)
ConfigServer Security & Firewall (CSF)
Content Delivery Network (CDN)
cPanel
cPanel Market
cPanel Store
cPanelID
cpdavd
cPHulk
cpmove
cpsrvd
CPU Load
cpuser (file)
Cron Job
crond or cron
Cross-Site Request Forgery Attack (XSRF or CSRF)
CURRENT
D
Daemon
Dangling Symlink
Data Center
Dedistribution
Default Address (cPanel Account Default Address)
Deprecated
Dictionary Attack
Digital Signature Algorithm (DSA)
Directory Harvest Attack (DHA)
Disk Space Quota
Distributed cPanel Account
DNS Zone
dnsadmin
Document root
Domain Control Validation
Domain Name
Domain Forwarding (Redirect)
Domain Name System (DNS)
Domain-Validated (DV) Certificate
DomainKeys Identified Mail (DKIM)
Domain-based Message Authentication, Reporting, and Conformance (DMARC)
Dovecot
DNSOnly®
Dynamic DNS (DDNS) Domain
E
EasyApache (EA)
EDGE
Elliptic Curve Digital Signature Algorithm (ECDSA)
Email Deliverability
End of Life (EOL)
Environment Variables
Error Pages
Exim
EXPERIMENTAL
Extended Fourth Filesystem (ext4)
Extended HELO (EHLO)
Extended SMTP (ESMTP)
Extended Validation (EV) Certificate
External Authentication
F
Feature
File Transfer Protocol (FTP)
Filesystem
Filter
Firewall
firewalld
Forceful Reboot
Forwarder
Fully Qualified Domain Name (FQDN)
G
Gem (RubyGem)
Generators (Web Statistics Generators)
Globally Unique Identifier (GUID)
GNU Privacy Guard (GnuPG)
Graceful Reboot
Greylisting
gzip
H
.htaccess
.htpasswd
Ham
HELO
Home Directory
Hostname
Hotlink (Inline Link)
httpd.conf

A

A (Address) Entry

A record that resides on your server and that contains your server’s hostname and IP address. The A entry tells DNS servers the identity of your server, which allows visitors to find your server on the internet. You can add an A entry for your hostname in WHM’s  Add an A Entry for Your Hostname  interface (WHM » Home » DNS Functions » Add an A Entry for Your Hostname).

Absolute Domain Name

Access Control List (ACL)

Permissions that a server’s owner grants to a reseller. You can define ACLs in the Edit Privileges section of WHM’s  Reseller Center  interface (WHM » Home » Resellers » Reseller Center).
Note:
Access Control Lists are not the same as Account Creation Limits.

Account

A record that lets you access privatized information. For example, your cPanel account lets you manage your website. You can create new cPanel & WHM accounts in WHM’s  Create a New Account  interface (WHM » Home » Account Functions » Create a New Account).

Account Enhancements

Account Enhancements allow you to control whether a cPanel account can access a third-party application, without modifying the account’s  package  settings.
  • To add or remove Account Enhancements from an existing cPanel account, use WHM’s  Modify an Account  interface (WHM » Home » Account Functions » Modify an Account).
  • You can add Account Enhancements to a new cPanel account in WHM’s  Create a New Account  interface (WHM » Home » Account Functions » Create a New Account).
Note:
If you have not installed any third-party applications that use Account Enhancements, the Account Enhancements section will not appear in WHM’s  Modify an Account  (WHM » Home » Account Functions » Modify an Account) or  Create a New Account  interfaces (WHM » Home » Account Functions » Create a New Account).
To configure a third-party application to use Account Enhancements, you must  add account enhancements  during the installation process.
To allow a  Reseller  to assign and unassign Account Enhancements, you must enable the Use Root Account Enhancements privilege in WHM’s  Edit Reseller Nameservers and Privileges  interface (WHM » Home » Resellers » Edit Reseller Nameservers and Privileges).

Account Suspension

The restriction of an account, usually because of unpaid fees. Hosting providers can suspend accounts until they receive payment, and then unsuspend the account.
  •  Suspended accounts retain all of their data , but visitors cannot access their websites.
  • You can suspend and unsuspend accounts in WHM’s  Manage Account Suspension  interface (WHM » Home » Account Functions » Manage Account Suspension).

Account-Level Filter

A rule that determines where to deliver email for a domain’s main email account that meets certain criteria.
More:
For more information, read our  How to Configure Mail Filters  documentation.

Addon Domain

An additional domain name that a cPanel account owns. The system stores each addon domain in its own configurable directory.
  • This allows website owners to manage multiple domains from a single cPanel account.
  • You can create and manage addon domains in cPanel’s  Domains  interface (cPanel » Home » Domains » Domains).
Note:
You must register addon domains with a  domain name registrar .

Addons (cPAddons)

Additional services for cPanel users (for example, blogs, message boards, and shopping carts). You can install cPAddons in WHM’s  Install cPAddons Site Software  interface (WHM » Home » cPanel » Install cPAddons Site Software).
Warning:
In cPanel & WHM version 104, we deprecated the cPAddons-related interfaces and plan to remove it in a future release. For more information, read our  cPanel Deprecation Plan .

Aliases

A second domain that points to a primary domain. For example, both http://www.cpanel.net/ and http://www.cpanel.com/ point to the same website, because cpanel.com is a domain alias for cpanel.net. This makes your website available from another domain name.

AlmaLinux OS

An open-source, community-driven Linux operating system distribution from  The AlmaLinux OS Foundation . The AlmaLinux OS is one of cPanel & WHM’s supported operating systems.
More:
For more information, read our  AlmaLinux Installation Guide  documentation.

Analog

 A program  that provides information about the visitors to a website in both graphical and statistical views. You can work with information from Analog in cPanel’s  Analog Stats  interface (cPanel » Home » Metrics » Analog Stats).

Ancestor Domain Control Validation

Successful  Domain Control Validation  (DCV) of a domain applies to all of its subdomains as well. For example, if the example.com domain succeeds, the store.example.com subdomain would also succeed.

Anonymous FTP

A protocol that lets visitors who don’t have FTP accounts upload and download files to and from a website. Although it poses security risks, anonymous FTP is convenient if you want to make files publicly available to download. You can configure anonymous FTP in cPanel’s  Anonymous FTP  interface (cPanel » Home » Files » Anonymous FTP).
Important:
When you set up anonymous FTP, you must change file permissions and directory access permissions in order to protect any sensitive information.

Apache®

 A web server software  that receives requests from browsers and serves web pages to the browsers. You can configure Apache in WHM’s  Apache Configuration  interface (WHM » Home » Service Configuration » Apache Configuration).

Apache Handler

 A record  that determines how the Apache software processes a specific type of file. By default, Apache only handles certain file types. You can configure Apache handlers in cPanel’s  Apache Handlers  interface (cPanel » Home » Advanced » Apache Handlers).

Apache SpamAssassin

An application that filters suspected spam. You can configure  Apache SpamAssassin  to filter spam more or less aggressively, based on the user’s needs.
  • You can enable this service in WHM’s  Tweak Settings  interface (WHM » Home » Server Configuration » Tweak Settings).
  • You can create spam filters in cPanel’s  Spam Filters  interface (cPanel » Home » Email » Spam Filters).

API Token

An authorization key hash that  lets third-party applications run API functions  with WHM account data. You can manage API tokens in WHM’s  Manage API Tokens  interface (WHM » Home » Development » Manage API Tokens).

Application Key (app_key)

A value that uniquely identifies each application within the cPanel interface.
  •  Each app_key value  is unique to a single item.
  • You can use these values when you develop  cPanel plugins .

Application Programming Interface (API)

A set of programming standards and tools that third-party or internal developers can use to interact with a software application. WebPros International, LLC provides  APIs  that you can use to customize and integrate with  cPanel or Webmail ,  WHM , and  Manage2 .

atd

A  daemon  that performs scheduled tasks for the at command on Linux operating systems. cPanel & WHM uses the at daemon to  check system health after updates .

Authenticated Received Chain (ARC)

An email protocol that helps combat  phishing ,  spoofing , and  spam . ARC verifies email authentication in messages that your server forwards or redirects. Google and other large email providers may require ARC headers in these types of messages.
If you enable ARC in cPanel & WHM, your server adds ARC headers to forwarded emails and emails sent via mailing lists. For more information, read our  Exim Configuration Manager Basic Editor  documentation.

Authentication

A process that lets you confirm the identity of someone with whom the server shares sensitive information. In software, authentication usually involves either a username and password set or a public and private key pair.
  • You can configure two-factor authentication (2FA) for  cPanel ,  WHM , and  Webmail  accounts.
  • Third-party integrators can use  several methods to authenticate with cPanel & WHM .

Authoritative Nameserver

A nameserver that returns responses to queries for one or more  DNS zones . Name Server (NS) records point to the domain’s authoritative nameserver. These nameservers don’t cache DNS information for related domains.
More:
For more information, read our  How to Set Up Nameservers in a cPanel & WHM Environment  documentation.

AutoConfig

A process that sets up users’ Thunderbird®, Outlook® or Outlook® Express accounts to receive their cPanel email.
More:
For more information, read our  AutoConfig and Autodiscover  documentation.

Autoresponder

Autoresponders allow you to automate replies to incoming email. You can configure automatic email response messages in cPanel’s  Autoresponders  interface (cPanel » Home » Email » Autoresponders).

AutoSSL

A feature in WHM that provides free,  Domain-Validated SSL certificates  to users’ domains.
  • The system periodically inspects users’ installed certificates and replaces those that are about to expire or that are insufficient to provide a baseline level of security.
  • This feature is available in WHM’s  Manage AutoSSL  interface (WHM » Home » SSL/TLS » Manage AutoSSL).

AWStats (Advanced Web Statistics)

A program that provides information about the visitors to a website.  AWStats  presents information in both graphical and statistical views. You can work with AWStats data in cPanel’s  Awstats  interface (cPanel » Home » Metrics » Awstats).

B

Backscatter

Backscatter is the term for bounced email messages (or failed Delivery Status Notifications) that the system erroneously sent to a domain when an attacker forged the domain’s name as the sender of spam.
  • Use  SPF  on your mail server to reduce backscatter.
  • Outscatter, misdirected bounces, blowback, and collateral spam are common synonyms for this term.

Backup

A copy of your website’s or server’s files, directories, databases, and email configurations.
  • We recommend that  cPanel users  store a backup copy of their website on a personal computer.
  • We recommend that  system administrators  create server and account backups often.

Bandwidth

The total size of all of the files that the system transferred to visitors’ computers.
  • Every time a visitor views a file, such as a web page, image, video, or audio file, the server transfers that file to the visitor’s computer.
  • Hosting providers often limit a site owner’s bandwidth because it can affect the performance of the server.
cPanel users can check bandwidth use in cPanel’s  Bandwidth  interface (cPanel » Home » Metrics » Bandwidth).

Bayes Testing (Bayesian Spam Filtering)

A method by which you can filter spam based on statistics. This method uses tokens (generally words) in emails to determine whether an incoming message is spam.
  • This technique relies on  Bayesian statistics . Bayesian classifiers correlate the use of tokens with spam and non-spam emails to calculate a probability that an email is or is not spam.
  • You can create spam filters in cPanel’s  Spam Filters  interface (cPanel » Home » Email » Spam Filters).
  • The Junk button in Roundcube also uses Bayesian spam filtering to train the system to recognize spam.

Berkeley Internet Name Domain (BIND)

The most prominently-used DNS server software. This is also referred to as named.
More:
For more information, visit the  BIND website .

Blackhole (Black Hole)

One of the options for how to handle mail that the default or catch-all email addresses of cPanel users receive.
  • This option discards mail after the server accepts it. For this reason, it may result in additional spam that your users receive, and places a larger load on your server than the fail option.
  • You can create filters in cPanel’s  Spam Filters  interface (cPanel » Home » Email » Spam Filters).

Blacklist

A method of access control for privileges to a defined list of users, programs, or network addresses. In cPanel & WHM, this term can refer to:
  • In  BoxTrapper , a list of rejected email senders. BoxTrapper automatically deletes any messages from senders who are on the blacklist.
  • In  cPHulk , a list of rejected IP addresses. cPHulk never allows logins to your server from IP addresses on the blacklist.
  • In  Exim , a list of IP addresses from which the system drops SMTP connections unconditionally.

Blocker

A condition that the system discovers and which doesn’t allow the system to perform a version update. The cPanel & WHM update process performs  compatibility checks to identify blockers  before it upgrades to a new version.

Bounce Message

An email reply that informs a sender that there was a problem with email delivery.

BoxTrapper

An application that requires senders to reply to a verification email in order to filter spam through challenge-response verification.
  • The system only accepts the original email after the sender replies to the verification message.
  • You can configure these settings in cPanel’s  BoxTrapper  interface (cPanel » Home » Email » BoxTrapper).
You may also see the following terms:
  • BoxTrapper Blacklist — A list of incoming email addresses that the  BoxTrapper  application automatically blocks. cPanel automatically sends a configurable warning message when it receives mail from a  blacklisted  address.
  • BoxTrapper Ignore List — A list of incoming email addresses that  BoxTrapper  automatically ignores.
Note:cPanel does not send a warning notification on receipt of mail from these addresses.
  • BoxTrapper Whitelist — A list of incoming email addresses that  BoxTrapper  automatically accepts.

Branding

Changes to the cPanel interface to match your company’s logo and brand. Branding changes also include updates to image assets or text labels. For more information, read our  Guide to cPanel Interface Customization and Branding .

Brute Force Attack

An attack during which the attacker enters a large number of combinations of characters in an attempt to decrypt a key. WHM includes  cPHulk , a protection system that lets you lock out brute force attackers after a specified number of failed attempts.

Bug

Build

A release of cPanel & WHM that uses a specific version number. WebPros International, LLC  releases cPanel & WHM builds in different stages  through our  named release tiers .

C

.crt File

The file for an  SSL certificate , an electronic document that ties a public key to a trusted entity. This electronic document is a key piece in the authentication process.

Cache

Stored information that the server accesses in lieu of the information source, saving bandwidth and time.
  • You can configure DNS record caches in WHM’s  DNS Zone Manager  interface (WHM » Home » DNS Functions » DNS Zone Manager).
  • You can configure disk usage cache data in WHM’s  Tweak Settings  interface (WHM » Home » Server Configuration » Tweak Settings).

Cascading Style Sheets (CSS)

A style sheet language in markup language that describes how a document, often in HTML, should appear. The  World Wide Web Consortium (W3C)  regulates CSS standards.

Catch-All Address (Domain Default Address)

Note:
This address is not the same as the cPanel account’s system user email account, which catches mail for domains that don’t have a configured default address.
The email address to which cPanel & WHM routes any email messages to nonexistent email accounts on a domain. You can set up a default address in cPanel’s  Default Address  interface (cPanel » Home » Email » Default Address).

Certificate

An electronic document that states the identity of a server. This lets end users know that they communicated with the correct website.
More:
For more information, read our  Guide to SSL .

Certificate Authority (CA)

An entity that issues digital certificates for server verification.
More:
For more information, read our  Guide to SSL .

Certificate Authority Authorization Record (CAA)

A DNS record that lets you specify which CA will issue an SSL certificate for a domain. If no CAA record exist for a domain, all CAs can issue a SSL certificate for a domain.
More:
For more information, read Wikipedia’s article about  DNS Certification Authority Authorization  and our our  Guide to SSL .

Certificate Authority Bundle (CA Bundle)

A file that contains details about an  SSL certificate , such as its issuer and that issuer’s certificates and chain of trust. Browsers include a built-in list of trusted certificate authorities, and compare their lists against CA bundles to determine whether to trust an authority.
More:
For more information, read our  Guide to SSL .

Certificate Signing Request (CSR)

A request that you send to a certificate authority for an identity certificate.
  • cPanel can generate a CSR for you. However, authorities vary with regard to the information that they require. Check their requirements before you apply for a certificate.
  • You can manage CSRs in the Certificate Signing Requrest (CSR) section of cPanel’s  SSL/TLS  interface (cPanel » Home » Security » SSL/TLS).
More:
For more information, read our  Guide to SSL .

Chain Of Trust

A record of which certificate authorities have vouched for the authenticity of other certificate authorities. For a certificate authority to sell certificates, another certificate authority must vouch for them.
More:
For more information, read our  Guide to SSL .

Change Log

A record of the changes that each development or production release of cPanel & WHM includes.
More:
For more information, read our  Change Log .

Character Set

A code that pairs a sequence of characters with a set of numbers, which allows a computer to store and transmit the characters. UTF-8 and ASCII are popular character sets.
More:
For more information, read Wikipedia’s article about  character sets .

Child Node

A non-authoritative  linked node  that receives tasks from a  parent node .

Classless Inter-Domain Routing (CIDR)

A routing method that lets you create routable subnets with finer granularity than the traditional network classes.
  • CIDR notation is the combination of an IP address and an abbreviated subnet mask. This mask consists of a slash (/) and the number of bits (which is between 0 and 32). Larger numbers indicate smaller network segments. For example, the CIDR notation 192.168.1.64/29 corresponds to an IP address of 192.168.1.64 and a subnet mask of 255.255.255.248, with a total of eight addresses in the segment.
  • Some cPanel & WHM interfaces (for example, cPanel’s  IP Blocker  interface (cPanel » Home » Security » IP Blocker)) use CIDR notation.

Client

Any application that accesses a service on another computer. When you work with cPanel & WHM, for example, you may need to configure  an SFTP client .
  • Web clients include browsers like as Google Chrome.
  • FTP clients include FileZilla® and Cyberduck.

CloudLinux

A commercial Linux operating system distribution from  CloudLinux, Inc.  CloudLinux is one of cPanel & WHM’s supported operating systems.
More:
For more information, read our  CloudLinux Installation Guide  documentation.

Cluster

A group of linked servers. cPanel & WHM has two separate clustering options:
  •  DNS clusters  keep DNS records synchronized among a group of computers and eliminates the need for manual updates.
  •  Configuration clusters  allow the system to replicate settings from a primary server to secondary servers.

Collection

A group of calendars, contacts, or other resources. In cPanel & WHM, a collection may be either standalone or shared with other email users of a cPanel account.
Email users manage their collections in Webmail’s  Calendars and Contacts Management  interface (Webmail » Calendars and Contacts Management) and share them in Webmail’s  Calendars and Contacts Sharing  interface (Webmail » Calendars and Contacts Sharing).

Command Line Interface (CLI)

A means of interacting with a computer that consists of entering commands. Unix systems often call this a shell.
More:
For more information, read our  How to Access the Command Line  documentation.

Common Gateway Interface (CGI)

A protocol that allows a web server to communicate with scripts and other software. The server usually stores CGI scripts in the cgi-bin directory.
More:
For more information, read the  Wikipedia Common Gateway Interface article .

Common Vulnerabilities and Exposures (CVE®) System

An archive of publicly-known security threats, vulnerabilities, and exposures. The  CVE system  assigns numbers (CVE identifiers), which provide a reference point when you evaluate the coverage and effectiveness of security tools and services.

Compiler

A computer program that translates source code that developers wrote into a language that a computer can read. This helps to protect your server from attacks and vulnerability exploits.
  • You will need to use a compiler with Ruby and other types of application.
  • Use WHM’s  Compiler Access  interface (WHM » Home » Security Center » Compiler Access) to manage your system’s complier access.

Comprehensive Perl Archive Network (CPAN)

The main repository of  Perl modules .
  • The  CPAN library  contains over 12,000 modules, most of which are free.
  • You can search CPAN for Perl modules and install them in cPanel’s  Perl Modules  interface (cPanel » Home » Software » Perl Modules).

ConfigServer Security & Firewall (CSF)

A stateful firewall, login/intrusion detection, and security plugin for Linux-based servers.
More:
For more information, visit the  CSF website .

Content Delivery Network (CDN)

A Content Delivery Network (CDN) is a  world-wide network of servers  that delivers data quickly to a world-wide network of users. This network architecture helps prevent unbalanced server loads and provides high availability.

cPanel

The companion software to  WHM . WebPros International, LLC designs cPanel to simplify website maintenance for website owners.
More:
For more information, read our  documentation for cPanel’s interfaces .

cPanel Market

A system that administrators can use to sell products from various vendors (for example, the cPanel Store) through the cPanel & WHM interface. For example, cPanel’s  SSL/TLS Wizard  interface (cPanel » Home » Security » SSL/TLS Wizard) uses the cPanel Market to sell  SSL certificates .
Note:
You can  create custom provider modules  for the cPanel Market.

cPanel Store

Our online store, through which customers can  purchase various services and products  such as licenses, support, and  SSL certificates .

cPanelID

Your login credentials for cPanel’s Store, ticket system, and  Manage2 . You can use your  cPanelID  as an  External Authentication  method.
  • Third-party developers can use  External Authentication modules  to authenticate with OpenID Connect-compliant identity providers.
  • You can configure External Authentication in WHM’s  Manage External Authentications  interface (WHM » Home » Security Center » Manage External Authentication).

cpdavd

cPanel’s WebDAV, calendars, and contacts  daemon . cpdavd provides access to cPanel’s  Web Disk  interface (cPanel » Home » Files » Web Disk),  Calendars and Contacts Management  interface (cPanel » Home » Email » Calendars and Contacts Management), and  Calendars and Contacts Sharing  interface (cPanel » Home » Email » Calendars and Contacts Sharing).

cPHulk

A WHM feature that helps  protect your web server  from malicious users who try to gain unauthorized access through brute force attacks.

cpmove

A copy of a user’s website, which you can create when you run the  /usr/local/cpanel/scripts/pkgaccount  script. The cpmove file is useful as a backup, and you can manually upload it to restore the user’s web files.

cpsrvd

cPanel Service  Daemon , the software that runs cPanel & WHM on your server.

CPU Load

The amount of processing capacity that programs on your server are consuming, in percentage format.
More:
For more information, read the  Troubleshooting High Server Loads on Linux Servers  forum article.

cpuser (file)

A file that has a cPanel account’s user information. It also contains the account’s resource limits, privileges, features, and  package extensions . The system stores a file for each cPanel user in the /var/cpanel/users directory, under the user’s username.

Cron Job

A task that the system runs at a scheduled interval. The tasks exist in the crontab Unix configuration file.
  • cPanel users can manage cron jobs with cPanel’s  Cron Jobs  interface (cPanel » Home » Advanced » Cron Jobs).
  • Server administrators can manage cron jobs with WHM’s  Configure cPanel Cron Jobs  interface (WHM » Home » Server Configuration » Configure cPanel Cron Jobs).

crond or cron

The cron daemon manages cron job scheduling. In Red Hat® systems, like AlmaLinux OS and CloudLinux, crond is the daemon’s name. In Debian® systems, like Ubuntu®, the daemon’s name is cron.
You can manage this service daemon from WHM’s  Service Manager  interface (WHM » Home » Service Configuration » Service Manager).
In cPanel & WHM, the restartsrv script’s crond service manages both the crond and cron daemons in their respective systems. For more information, read our  The restartsrv script  documentation.

Cross-Site Request Forgery Attack (XSRF or CSRF)

 A type of malicious attack  that forces a user to execute unauthorized commands, usually through a link, to exploit a trusted website.
  • To help prevent these attacks, cPanel & WHM requires every request to contain a unique per-session security token.
  • One-click attacks or session riding are common synonyms for this term.

CURRENT

One of cPanel & WHM’s  release tiers . We have tested and verified versions on this tier, but they may not contain all of the proposed functionality of a release.
More:
For more information, read our  Product Versions and the Release Process  documentation.

D

Daemon

A computer program that runs as a background process. The user cannot view or directly control this process.
More:
For more information, read our  The cPanel & WHM Service Daemons  documentation.

Dangling Symlink

A symbolic link that refers to a pathname that doesn’t exist. For example, a symbolic link could point to a file that doesn’t exist.

Data Center

A facility that houses servers. A data center is generally a safe place to keep a server because it typically includes backup power supplies, multiple communication connections, and environmental controls.

Dedistribution

The process of moving some or all of a  distributed cPanel account ’s functionality from a  child node  back to the  parent node . For example, returning a cPanel account’s mail functionality from a  Mail Node  child node to the parent node.

Default Address (cPanel Account Default Address)

Note:
This address is not the same as a domain’s default address, which catches mail for a specific domain after you configure it.
The email address to which cPanel & WHM routes any email messages to nonexistent email accounts or other invalid recipients on your cPanel account. You can check your cPanel account’s default address inbox in cPanel’s  Manage Email Accounts  interface (cPanel » Home » Email » Manage Email Accounts).

Deprecated

A term that WebPros International, LLC uses to describe a feature that we  no longer support or will remove  in an upcoming release.

Dictionary Attack

A method in which a malicious user tries to guess a password with words from a dictionary.
  • This attack is similar to a  brute force attack .
  • To help prevent this attack type, enable the Dictionary attack protection setting in WHM’s  Exim Configuration Manager  interface (WHM » Home » Service Configuration » Exim Configuration Manager).

Digital Signature Algorithm (DSA)

A method that you can use to generate public and private keys for the signing of data.

Directory Harvest Attack (DHA)

A  brute force attack  technique. Spammers attempt to find valid email addresses on a server through guesswork and various permutations of common addresses. WHM includes  cPHulk , a protection system that lets you lock out brute force attackers after a specified number of failed attempts.

Disk Space Quota

A limit that hosting providers place on the amount of disk space that an account may use.
  • Website owners can locate their usage data in cPanel’s  Disk Usage  interface (cPanel » Home » Files » Disk Usage).
  • Server administrators manage users’ disk space quotas in WHM’s  Quota Modification  interface (WHM » Home » Account Functions » Quota Modification).

Distributed cPanel Account

A cPanel account that exists on two or more  linked nodes .

DNS Zone

The administrative part of the  Domain Name System (DNS) . This directs internet traffic to the correct location. For example, example.com is a DNS zone with servers that direct its internet traffic. You can add DNS zones to the server in WHM’s  Add a DNS Zone  interface (WHM » Home » DNS Functions » Add a DNS Zone).

dnsadmin

A program that manages DNS services and DNS clustering.
  •  DNS clusters  use dnsadmin.
  • Third-party integrators can create  custom dnsadmin plugins .

Document root

  • Your primary domain’s document root typically defaults to the public_html directory.
  • The document root directories of any addon domains or subdomains depend on your server’s settings.

Domain Control Validation

A  CA  uses Domain Control Validation (DCV) to verify that a certificate requester owns the domain before issuing the certificate. The CA can use one of the three following DCV methods to verify ownership:
  • Email — Send a validation email to the administrative contact for the domain.
  • DNS — Check a special CNAME record for the domain in DNS.
  • HTTP — Check a hashed text file on the requester’s website.

Domain Name

The name that a site owner gives to a website, which appears in the website’s URL and email addresses.
  • Generally, domains use the example.com format, where example is the domain name and com is the  top-level domain .
  • You can add and manage domains in cPanel’s  Domains  interface (cPanel » Home » Domains » Domains).

Domain Forwarding (Redirect)

A technique that allows you or your users to automatically send visitors to a domain when they access another domain. For example, a user may reach example.com when they enter example2.com. You can set up and manage domain forwarding in WHM’s  Setup/Edit Domain Forwarding  interface (WHM » Home » DNS Functions » Setup/Edit Domain Forwarding).

Domain Name System (DNS)

The component of the internet that converts human-readable domain names (for example, www.example.com) into computer-readable IP addresses (for example, 93.184.216.34).
  • A DNS record can specify which mail servers exist for a given domain. These records also identify which nameservers contain authoritative information about your domains and services.
  • The nameserver software on your server manages nameserver records. cPanel & WHM offers BIND and PowerDNS as nameserver software options.
Warning:We removed the MyDNS and NSD nameservers in cPanel & WHM version 106 and later. We strongly recommend that you migrate to PowerDNS. For more information, read our  cPanel Deprecation Plan .

Domain-Validated (DV) Certificate

A digital certificate for  SSL/TLS  verification. The  certificate authority (CA)  verifies that the applicant controls the DNS domain via email, phone, or other method.
  • These certificates are the least secure level of domain validation, since the CA does not attempt to verify who the domain owner actually is.
  • You can purchase and install DV certificates in cPanel’s  SSL/TLS Wizard  interface (cPanel » Home » Security » SSL/TLS Wizard).

DomainKeys Identified Mail (DKIM)

An email authentication method which attempts to verify that a message actually came from the domain it appears to have originated from. You can enable DKIM in WHM’s  Enable DKIM/SPF Globally  interface (WHM » Home » DNS Functions » Enable DKIM/SPF Globally).

Domain-based Message Authentication, Reporting, and Conformance (DMARC)

DMARC (Domain-based Message Authentication, Reporting & Conformance) is a technical specification to help reduce the potential for email-based abuse. A DMARC policy uses DNS to confirm that an email message uses a valid  DKIM  and  SPF  record, and that the From: header matches those records.
Many large email networks require that you use a DMARC policy to help protect their users from spam email. To prevent email rejections or spam flags within these networks, your domain must use a DMARC policy.
  • To set a default DMARC policy when you create a new account, select the Enable DMARC on this account. checkbox in WHM’s  Create a New Account  interface (WHM » Home » Account Functions » Create a New Account).
  • To apply a default DMARC policy to all domains on the server, use WHM’s  Email DNS Record Manager  interface (WHM » Home » DNS Functions » Email DNS Record Manager).
  • To create a custom DMARC record or modify an existing DMARC record for a domain, use WHM’s  DNS Zone Manager  interface (WHM » Home » DNS Functions » DNS Zone Manager) or cPanel’s  Zone Editor  interface (cPanel » Home » Domain» Zone Editor).
More:

Dovecot

An  open-source mail server software  that has optimal security. You can configure your Dovecot mail server settings in WHM’s  Mailserver Configuration  interface (WHM » Home » Service Configuration » Mailserver Configuration).

DNSOnly®

A version of cPanel & WHM that lets you run a dedicated physical nameserver. This version of cPanel & WHM is extremely minimal and only replicates DNS zones to your other servers.
More:
For more information, read our  cPanel DNSOnly  documentation.

Dynamic DNS (DDNS) Domain

This type of domain simplifies access to a network that uses a dynamic IP address via a  webcall  URL. For example, a user can use this domain to access their home network, even when the IP address changes. For more information, read our  Dynamic DNS  feature documentation.

E

EasyApache (EA)

A part of cPanel & WHM that installs, modifies, and validates your Apache web server, PHP, and other components.
More:
For more information, read our  EasyApache  documentation.

EDGE

One of cPanel & WHM’s  release tiers .
  • Versions on this tier have only had rudimentary testing and are subject to further modification.
  • We don’t recommend this tier for production servers.
More:
For more information, read our  Product Versions and the Release Process  documentation.

Elliptic Curve Digital Signature Algorithm (ECDSA)

A variant of  Digital Signature Algorithm  that uses  elliptic-curve cryptography (ECC) . ECDSA provides equivalent security to RSA keys using smaller key sizes. As a result, ECDSA keys generate smaller certificates. Smaller certificates can result in faster connections and website loading times.

Email Deliverability

Whether a system can deliver email to recipients. Email deliverability often gauges whether email campaigns will succeed, and it can help you identify mail-related DNS problems. You can view email deliverability information in cPanel’s  Email Deliverability  interface (cPanel » Home » Email » Email Deliverability).

End of Life (EOL)

The stage of software’s lifecycle when the author no longer provides security updates or bug fixes. When a version of WebPros International, LLC’s software, an operating system, or third-party software that ships with cPanel & WHM reaches EOL, we can’t guarantee support for that version of software.
More:
For more information, read our  Third-Party Software End of Life Policy  documentation.

Environment Variables

Values that advanced administrators place within specific files on the server to change the behavior of  Apache ,  PHP , and other systems.
Note:
Third-party integrators can use  cPanel environment variables  in the LiveAPI system and dynamicui.conf files.

Error Pages

Pages that  display warning messages  when visitors encounter problems while they try to access your site. You can customize these pages in cPanel’s  Error Pages  interface (cPanel » Home » Advanced » Error Pages).

Exim

A  free mail transfer agent  software that is highly flexible and easily configurable. You can modify your Exim configuration in WHM’s  Exim Configuration Manager  interface (WHM » Home » Service Configuration » Exim Configuration Manager).

EXPERIMENTAL

An  unstable feature or setting  that may cause unintended consequences. Exercise extreme caution if you enable an EXPERIMENTAL feature or setting.
Important:
These features may not function with other features or settings.
These features are not currently effective security controls.
EXPERIMENTAL features don’t qualify for our security bounty.

Extended Fourth Filesystem (ext4)

A journaled filesystem that Linux servers often use. ext4 is the successor to the ext3 filesystem. We  require  ext4 for all cPanel & WHM installations.

Extended HELO (EHLO)

See also:  HELO 
An  Extended Simple Mail Transfer Protocol (ESMTP)  command that a mail server or client sends to identify itself when it connects with another mail server.
  • This command initiates the process of sending an email and follows with the server sending its domain name.
  • The esmtp command notifies the receiving server or client that the sending server supports ESMTP extensions.

Extended SMTP (ESMTP)

An extension of the original  Simple Mail Transfer Protocol (SMTP) ’s protocols. ESMTP sends an  EHLO  request to a mail server or client to identify the server’s supported protocol. The server returns a list of its available ESMTP commands.

Extended Validation (EV) Certificate

A digital certificate for  SSL/TLS  verification. The  certificate authority (CA)  verifies that the applicant controls the DNS domain with a comprehensive identity validation process.
  • These certificates enable HTTPS on a user’s web browser address bar and state the name of the verified owner.
  • These certificates are the most secure level of domain validation.
  • You can purchase and install certificates in cPanel’s  SSL/TLS Wizard  interface (cPanel » Home » Security » SSL/TLS Wizard).

External Authentication

This feature allows system administrators to grant users the ability to access their cPanel accounts with an external account provider, such as a cPanel ID or with a Google® account.
  • Third-party developers can use  External Authentication modules  to authenticate with OpenID Connect-compliant identity providers.
  • You can configure External Authentication in WHM’s  Manage External Authentications  interface (WHM » Home » Security Center » Manage External Authentication).

F

Feature

See  Bug .

File Transfer Protocol (FTP)

A method that you can use to transfer files from one computer to another. cPanel & WHM includes an FTP server that website owners can configure.
  • You must install an FTP client (for example, FileZilla and Cyberduck) on the local computer in order to send files to and receive files from the FTP server.
  • You can select an FTP server in WHM’s  FTP Server Selection  interface (WHM » Home » Service Configuration » FTP Server Selection) and configure it in WHM’s  FTP Server Configuration  interface (WHM » Home » Service Configuration » FTP Server Configuration).
  • You can create and manage FTP accounts in cPanel’s  FTP Accounts  interface (cPanel » Home » Files » FTP Accounts).

Filesystem

The system that the operating system uses to manage files and directories. If your server uses multiple partitions, each partition might use a different filesystem.

Filter

In cPanel, a tool that processes email based on your preferences. For example, a filter can automatically discard spam or save mail from a specified sender to its own folder.
  • You can apply filters to the main email account on a domain with the  Global Email Filters  interface (cPanel » Home » Email » Global Email Filters).
  • You can customize filters for each individual account with the  Email Filters  interface (cPanel » Home » Email » Email Filters).
  • WHM users can set up more types of filters, like  Exim filters .

Firewall

A security application that protects servers from intrusion by hackers. For example, CSF is a popular firewall for Linux systems. Linux systems also include a built-in firewall,  iptables .
More:
For more information, read our  How to Configure Your Firewall for cPanel & WHM Services  documentation.

firewalld

A firewall tool for Linux operating systems. It dynamically manages network and firewall zones and defines trust levels.
More:
For more information, visit the  firewalld  website.

Forceful Reboot

One of the two methods that you can use to restart your server. This method forces the server to restart regardless of any errors that it encounters.
  • Only use a forceful reboot if you cannot  reboot gracefully , because it can result in data loss.
  • You can perform forceful and graceful reboots  in the WHM interface .

Forwarder

A tool that lets you forward a copy of every email message that you receive to another address. When a forwarder exists, you still receive mail at the original recipient address.
  • If you create a forwarder before you create the original address, the system will forward messages to the end address but not to the original address, because it does not exist.
  • You can create and manage forwarders in cPanel’s  Forwarders  interface (cPanel » Home » Email » Forwarders).

Fully Qualified Domain Name (FQDN)

A name that uniquely defines a domain’s location.
  • The FQDN generally uses the host.example.com. format, with a trailing dot. However, for cPanel & WHM, a final dot is unnecessary, but the domain name must contain at least two dots.
  • You must write FQDNs in lowercase letters.

G

Gem (RubyGem)

A piece of software in the Ruby language. These exist in the RubyGems repository.
More:
For more information, visit the  RubyGems  documentation.

Generators (Web Statistics Generators)

Software applications that compile log statistics for your web server. For example, they can report the amount of bandwidth that each domain has transferred.
  • cPanel & WHM includes three statistics generators:
  •  Analog 
  •  AWStats 
  •  Webalizer 
  • Server administrators can manage their server’s web statistics and software in WHM’s  Statistics Software Configuration  interface (WHM » Home » Server Configuration » Statistics Software Configuration).

Globally Unique Identifier (GUID)

A value that the system uses to identify a resource, similar to  UUID . UUID is the more common identifier while Microsoft products are the main users of GUID.

GNU Privacy Guard (GnuPG)

A  suite of tools  that you can use for data encryption and signing. Generally, you will use these tools for signing emails. You can create and manage GnuPG keys in cPanel’s  Encryption  interface (cPanel » Home » Email » Encryption).

Graceful Reboot

This method stores new system information before the server shuts down and is the preferred way to restart your server.
  • This is the opposite of a  forceful reboot .
  • You can perform forceful and graceful reboots  in the WHM interface .

Greylisting

A service that protects a server against unwanted email or spam. When you enable greylisting in WHM’s  Greylisting  interface (WHM » Home » Email » Greylisting), the mail server temporarily rejects any email from a sender that the server does not recognize.
  • If the email is legitimate, the originating server attempts to send it again after a delay.
  • After sufficient time passes, the server accepts the email.

gzip

A program that compresses files for disk space conservation, minimizes transfer times, and makes the transfer of multiple files easier.
  • The compressed files use the .gz file extension.
  • Unix and Linux systems often use gzip with the  tar  command to create a tarball file, which uses the .tar.gz file extension.
  • You can set the system’s gzip compression level in WHM’s  Tweak Settings  interface (WHM » Home » Server Configuration » weak Settings).

H

.htaccess

A file that resides in a specific directory and contains the directory’s configuration information. The .htaccess file may also contain authentication instructions.

.htpasswd

A file that resides in a specific directory along with an .htaccess file. This file contains encrypted password information when the owner has set up authentication for the directory.
Note:
You can use cPanel’s  Directory Privacy  interface (cPanel » Home » Files » Directory Privacy) to configure directory privacy.

Ham

Legitimate messages that the system marks as spam. Use the Not junk button in Roundcube to train the system to recognize ham.

HELO

See also:  EHLO 
A  Simple Mail Transfer Protocol (SMTP)  command that a mail server or client sends to identify itself when it connects with another mail server. This command initiates the process of sending of an email and follows with the server sending its domain name. Older mail clients use this command because these clients don’t require service extensions.

Home Directory

A cPanel account’s highest-level directory, which contains all of the files and directories that the account’s websites use. Visitors cannot view the files in a home directory unless they reside in the public_html directory or one of its subdirectories.

Hostname

The unique, human-recognizable name for a server across the internet (for example, host.example.com).
  • System administrators can specify or change a server’s hostname with WHM’s  Change Hostname  interface (WHM » Home » Networking Setup » Change Hostname).
  • The server hostname is distinct from your  domain name .

Hotlink (Inline Link)

A direct link that embeds a file, such as an image or video, from your site into another website.
  • When another site embeds your files, it uses your bandwidth to serve those files.
  • You can prevent hotlinking in cPanel’s  Hotlink Protection  interface (cPanel » Home » Security » Hotlink Protection).

httpd.conf

The configuration file for the  Apache web server .