cPanel & WHM Glossary
For cPanel version 11.40
An additional domain name associated with a cPanel account. Each addon domain is stored in its own directory which website owners can configure. This allows website owners to manage multiple domains from a single cPanel account. Addon domains must be registered with a domain name registrar
A program that provides information about the visitors to a website in both graphical and statistical views. More information about Analog can be found at http://www.analog.cx/
A process whereby visitors without FTP accounts may upload and download files to and from a website. Although it poses security risks, anonymous FTP can be convenient if the site owner wishes to make files publicly available for downloading. When setting up anonymous FTP, it is important to protect any sensitive information by changing file permissions and directory access permissions.
A program that receives requests from web browsers. It then responds by “serving” web pages to the browsers; for this reason, it’s called web server software.
A daemon for the at command in Linux operating systems, which performs scheduled tasks.
A process for confirming the identity of someone with whom the server will share sensitive information. On the web, authentication usually involves either a username and password set or a public/private key pair.
AWStats (Advanced Web Statistics):
A program that provides information about the visitors to a website in both graphical and statistical views. More information about AWStats can be found at its website: http://awstats.sourceforge.net/
The amount of data transferred to and from a server. Every time a visitor views a file (whether it’s a web page, image, video, or audio file), that file has to be transferred to the visitor’s computer. Bandwidth is the total size of all these files transferred to visitors’ computers. Hosting providers often limit a site owner's bandwidth, as it can affect the performance of the server.
An application included with cPanel that filters spam by requiring would-be senders to reply to a verification email (also known as challenge-response verification). Only after the sender is verified through the reply will his or her original email be accepted.
A list of email addresses from which incoming mail will be automatically blocked by the BoxTrapper application. cPanel automatically sends a configurable warning message upon receipt of mail from a blacklisted address. See also BoxTrapper Ignore List
and BoxTrapper Whitelist
BoxTrapper Ignore List:
A list of email addresses from which incoming mail will be blocked. cPanel does not send a warning message upon receipt of mail from an address ignored by the BoxTrapper application. See also BoxTrapper Blacklist
and BoxTrapper Whitelist
A list of email addresses from which incoming mail will automatically be accepted by the BoxTrapper application. See also BoxTrapper Ignore List
and BoxTrapper Blacklist
Formerly, a minor version of cPanel. (These are now referred to as Release Tiers
A unit of measure for digital memory storage. One byte represents a group of eight bits (binary digits).
The email address to which cPanel & WHM routes any email message sent to email accounts which do not exist at a domain. Also known as a Default Address
CGI (Common Gateway Interface):
A protocol that lets a web server communicate with scripts and other software. cPanel’s CGI Center
provides an array of CGI scripts that let website owners generate and manage useful features for websites, including a guestbook, clock, hit counter, countdown clock, and banner ads.
CIDR (Classless Inter-Domain Routing):
A routing method that assigns each Internet user to a four-part IP address, with each part separated by a decimal, followed by a slash and a number between 0 and 32.
CLI (Command Line Interface):
A means of communicating with a computer by typing commands. On Unix systems, this is also often called a shell
Pieces of software that website owners can install on a website through cPanel. cPAddons provide useful tools to a website. Common examples include bulletin boards, chat programs, and online shopping carts.
The replacement for the older DomainKeys
protocol. Like DomainKeys, DKIM attempts to verify the origins of email messages.
The email address to which cPanel routes any email message sent to email accounts which do not exist at a domain. Also known as a Catch-All Address
A repository for files, analogous to a file folder on a personal computer. In website management, a directory will contain the website's files.
DNS (Domain Name System):
The component of the Internet which acts as a “phone book,” converting human-readable domain names (such as
) into computer-readable IP addresses (such as
, in the case of
The name a site owner gives a website, which will appear in the website’s URL and email addresses. Usually seen as
is meant for the domain name.
FQDN (Fully Qualified Domain Name):
A name that uniquely defines a domain’s location. It is usually seen as
with a trailing dot. For the purposes of cPanel, including a final dot is not necessary, but the domain name must contain at least 2 dots. FQDNs must be written in lowercase letters.
A Microsoft® application that allows site owners to edit a web page in WYSIWYG (“what-you-see-is-what-you-get”) format, rather than using raw HTML code and CSS. WHM provides FrontPage extensions, so site owners can publish their sites using FrontPage, allowing them to skip the FTP process.
FTP (File Transfer Protocol):
A method of transferring files from one computer to another. cPanel & WHM comes equipped with an FTP server that can be configured to the website owner's preference. An FTP client must be installed on the local computer in order to send files to and receive files from the FTP server. Some FTP clients include FileZilla (for Windows®, Linux, and Unix), and Cyberduck (for Mac®).
A unit of measure for digital memory storage. One gigabyte is equal to 1,024 megabytes, 1,048,576 kilobytes, or 1,073,741,824 bytes.
A program which compresses files for disk space conservation, minimizing transfer times, and making the transfer of multiple files easier. The compressed files use the filename extension
. In Unix and Linux systems,
is often used with
to create a “tarball” file (which ends with
A cPanel account’s highest-level directory, which contains all the files and directories used by websites managed by the account. Files placed in a home directory are not viewable online unless they reside in the
directory or a subdirectory of
A file that resides in a specific directory, and contains configuration information applying to that directory. The
file may also contain authentication instructions.
HTML (Hypertext Markup Language):
The language in which most pages on the World Wide Web are written.
IMAP (Internet Message Access Protocol):
Along with POP3, one of the two most widely used email transfer methods. IMAP synchronizes email account information with the mail server on a regular basis. If a user logs into multiple computers to check email, IMAP will allow the user to see what messages they have viewed, replied to, forwarded, etc. POP3 does not display this information.
The page, most often titled
, viewed by default when a visitor accesses a directory of a website. If no index page exists for the specified directory, the visitor will see a list of files in that directory, unless indexing is disabled in cPanel.
IP (Internet Protocol) Address
: A number that identifies a computer on a network, making it possible for other computers to find and communicate with it.
In cryptography, a key is used to encrypt or decrypt information. Keys are an important part of encryption and security and should be guarded appropriately. A key file is saved with the filename extension
A unit of measure for digital memory storage. One kilobyte is equal to 1,024 bytes.
A file, automatically created by the server, that records activities performed by specific programs and applications on the server. For instance, error logs are lists, generated by Apache, of errors that visitors have encountered on a website.
A web analytics program that delivers information about your website's traffic, keywords, and content. For more information about Logaholic, please visit http://www.logaholic.com
A list of email addresses which list members can use to communicate. Alternatively, such a list can be used to send email messages to a large group of people. cPanel & WHM uses a program called Mailman for mailing list software. For more information, please see the Mailman website, http://www.list.org
A unit of measure for digital memory storage. One megabyte is equal to 1,024 kilobytes, or 1,048,576 bytes.
MX (Mail eXchanger) Entry:
A record that specifies where email should be sent for a domain, as it contains the mail server’s IP address. When using an email scanning service or custom mail delivery, the server administrator may need to change the MX record for a domain using the Edit MX Entry
feature in WHM.
A relational database management tool and server, as well as the type of database it manages. Databases are an integral part of web applications, such as bulletin boards and blogs. cPanel provides an integrated MySQL interface as well as a MySQL database editing tool called phpMyAdmin. WHM lets server administrator manage MySQL database services via the SQL Services
A piece of software that obtains DNS information from a physical nameserver, a computer that contains a list of domain names and their corresponding IP addresses. These computers are spread through the Internet and allow visitors to access a domain via its IP address. Nameserver software gathers data about domains over time; therefore, changes to DNS records can take up to a week to reach all the nameservers on the Internet (or “propagate”).
NAT (Network Address Translation):
A process which maps an IP address on one network to a different IP address or addresses on another network. cPanel & WHM supports 1:1 NAT, which maps a single IP address on the local network with single IP address on the public network.
An alias domain name for your cPanel account's primary domain that shares the account's home directory. With a parked domain, you can point multiple domains to the same home directory and deliver the same content on each domain. For example, if you park
on top of
, visitors will see the same content on both domains.
Known for its ability to process text, Perl is a useful language for web applications. Perl applications are commonly found as
files and may require Perl modules. Perl modules can be installed from cPanel (using the Perl Modules
screen) and in WHM (using the Install a Perl Module
A piece of software written in the Perl language. Modules are common pieces of software that are reused often. For example, rather than writing a set of functions to display calendars, a user can simply use a calendar module.
A computer scripting language in which many web-based applications are written. PHP applications are commonly found with the filename extensions
. Some PHP applications require PEAR packages, which can be installed in cPanel through the PHP PEAR Packages
feature and in WHM through the Module Installers
A piece of software written in the PHP language.
A graphical application that allows server administrators to manipulate and manage MySQL databases over the Internet. Full documentation for phpMyAdmin can be found at its creators’ website: http://www.phpmyadmin.net
POP3 (Post Office Protocol version 3):
Along with IMAP, one of the two most widely used email transfer methods. POP3 simply copies every message in an email account to a local computer, removing it from the mail server. No information is sent back to the email account about message replies, forwarding, etc. If an account owner uses multiple computers to check email, it is advisable to use IMAP instead of POP3.
Short for a proxy server
. This server receives requests from users and forwards those requests to other servers.
A subdirectory, located inside the home directory, that contains files that are publicly accessible via HTTP. The
directory is a link to
. Any files and folders inside of
are visible over the Internet, unless the website owner specifically protects them with password protection or using the
To send users who access a domain to another domain. For example, a user may reach
. cPanel allows website owners to set up either temporary or permanent redirects. See also domain forwarding
A web page which links to a site; also called an “HTTP referer.” This spelling is the industry standard term, though it is based on a misspelling of “referrer.”
These exist in four types which are, in order from least to most stable, EDGE, CURRENT, RELEASE, and STABLE. Please visit our documentation on cPanel versions and the release process
for an in-depth discussion of Release Tiers.
1) Specific to Unix and Unix-based systems, the system account, used by a system administrator, that carries full privileges for configuring a computer system. Also called “superuser.” 2) The highest level directory in a Unix or Unix-based system, usually notated by a forward slash (
Software that allows a user to interact with a computer. Many Unix shells allow the user to type commands, and are often referred to as CLIs, or command line interfaces.
SMTP (Simple Mail Transfer Protocol):
This protocol is the standard for transmitting email messages across the Internet. It is namely used for sending
mail to a mail server’s relayer.
SNI (Server Name Indication):
A TLS extension which allows you to host multiple SSL Certificates, for different domains, on the same IP address. SNI indicates which hostname the client will connect to at the start of the handshake process. Users who are on shared servers that support SNI can install their own certificates and bypass the need for a dedicated IP address.
Chiefly, unsolicited email sent in bulk, usually by an automated system. As spam is considered a costly nuisance to the recipient, cPanel includes features like SpamAssassin
that can cut down on the amount of spam received. Server administrators can use the Tweak Settings
screen to enable these services for their users.
An application which can filter suspected spam. SpamAssassin
can be configured to filter spam more or less aggressively, according to the user's needs. Learn more about SpamAssassin
. Server administrators can use the Tweak Settings
screen to enable this service for their users.
An attack wherein the attacker conceals his identity by appearing as another user through the falsification of data, such as email headers. Enabling SPF makes it more difficult for spammers to spoof a domain.
SSH (Secure Shell Handler):
A network protocol that allows a user to log into a remote machine securely. cPanel & WHM can create keys for authenticating a user's identity during SSH login, and lets users manage SSH keys.
SSL (Secure Sockets Layer)/TLS (Transport Layer Security):
TLS is simply the more recent version of SSL. Both are cryptographic schemes that allow for secure interaction between a web browser and a web server. All sensitive data (credit card numbers, login information, etc) that is transmitted over the Internet should be protected by SSL/TLS. Website owners can install an SSL certificate on a website (via the Install a SSL Certificate and Setup the Domain
feature) to allow the site to be protected by SSL/TLS.
An electronic document (using the filename extension
) which binds a public key to an identity consisting of an email address, company, and location. This electronic document is a key piece in an authentication process.
A subsection of a website that exists as a subdirectory in the website owner's home folder. If the domain were
, then the subdomain URL would appear as
URL (Universal Resource Locator):
On the web, a URL is a string of characters that identifies the location of a website. Since IP addresses are difficult to remember, URLs are used instead. For example, it is much easier to remember to go to
. URL is often used synonymously with the terms “URI” and “web address,” although there are technical differences among the three.
A feature of cPanel that lets website owners manipulate web files by dragging and dropping, just as one would on a local computer’s operating system.
A program that displays various statistics for a website using tables and graphs. Full documentation for The Webalizer can be found at its creators’ website: http://www.webalizer.com
Any application which allows website owners to access email through a web browser. The main advantage to webmail is the ability to access the email account from any computer connected to the Internet without having to install or configure a specific mail program.
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