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Technical Glossary, Reference

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There are currently 158 names in this directory
Addon Domain
An additional domain name associated with a cPanel account. Each addon domain is stored in its own directory that can be configured during its creation. This allows clients to manage multiple domains from a single cPanel account. Addon domains must be registered with a domain registrar and configured to point to our servers to properly function.

AdSense (Google AdSense)
An advertising placement service by Google. The program is designed for website publishers who want to display targeted text, video or image advertisements on website pages and earn money when site visitors view or click the ads.

Adwords (Google Adwords)
is an advertising service by Google for businesses wanting to display ads on Google and its advertising network. The AdWords program enables businesses to set a budget for advertising and only pay when people click the ads. The ad service is largely focused on keywords.

Anonymous FTP
A process whereby visitors without FTP accounts may upload and download files to and from a website. Because it poses security risks, we do not offer anonymous FTP.

A program that receives requests from web browsers and responds by "serving" web pages to the browser. For this reason, it's called a web server.

Apache Handler
A means of telling the Apache software how to process a given type of file. By default, Apache only handles certain file types. You can configure Apache handlers for other file types using an .htaccess file. For more information, see Apache's handler documentation.

ASCII (American Standard Code for Information Interchange)
The world-wide standard of code numbers used by computers to represent all the upper- and lower-case Latin letters, numbers, and punctuation. There are 128 standard ASCII codes, each of which can be represented by a 7-digit binary number, 0000000 through 1111111.

Auto Responder
Auto responders allow you to automate replies to incoming email. In cPanel, this feature can be useful for confirming the receipt of mail, or for informing correspondents that the recipient is unavailable - for example, while on vacation.

A copy of your website's files, directories, and databases. Keeping a current backup of your website either remotely or on your personal computer is highly recommended.

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 is transferred to the visitor's computer. Bandwidth is the total size of all these files transferred to visitors' computers. Using too much bandwidth can affect the performance of the server.

Bandwidth Limit
A limit imposed on the amount of data an account is allowed to transfer per month.

Bounce Message
An email reply informing a sender that there was a problem delivering an email.

Brute Force Attack
A type of attack wherein the attacker enters a large number of combinations of characters, in an attempt to decrypt a key. Similar to a Dictionary Attack.

A section of memory or the Hard Drive where data can be stored for rapid or frequent access.

Catch-All Address
The email address to which cPanel routes any email message sent to email accounts that do not exist on a domain. Also known as a Default Address.

An electronic document that states the identity of a server so that the end user knows that he or she is communicating with the correct website.

Certificate Authority
An entity that issues digital certificates for server verification.

Certificate Authority (CA) Bundle
A file on the server that verifies that your public and private keys were issued by a trusted entity. If your SSL provider sent you a CA bundle file, you can install it using the "Install SSL Certificate" feature in cPanel. Also known as an Intermediate Certificate.

CGI (Common Gateway Interface)
A protocol that lets a web server communicate with scripts and other software.

The most common directory to store CGI programs on a web server. The "bin" part of "cgi-bin" is an abbreviation of "binary", dating back to when programs were referred to as "binaries".

An SSH command that allows you to set permissions (read, write, or execute) on a file or directory.

CLI (Command Line Interface)
A means of communicating with a server by typing commands. This is also often called a shell.

Client / Server
Computer technology that separates computers and their users into two categories. When you want information from a computer on the Internet, you are a client. The computer that delivers the information is the server. A server both stores information and makes it available to any authorized client who requests the information.

A piece of information (login names, passwords, online "shopping cart" items, user preferences, etc.) sent by a web server to a web browser and saved to the computer. These "cookies" can then be used at a later date to restore the information when the web server is accessed again. Cookies are usually set to expire after a predetermined amount of time.

A web-based control panel designed to simplify website maintenance for website owners.

CPU Load
The amount of processing ability currently being consumed by programs on the server, measured in a percentage. More information about CPU loads can be found here.

Cron Job
A command on a server, executed at regular intervals. These commands are stored in a configuration file called crontab. You can manage your cron jobs using the "Cron Manager" feature in cPanel.

CRT (Certificate) File
An SSL certificate, an electronic document which ties a public key to a trusted entity. This electronic document is a key piece in an authentication process.

CSR (Certificate Signing Request)
A request, which you send to a Certificate Authority, for an SSL certificate. You can generate a CSR using the "Generate CSR" feature in cPanel, but since authorities vary with regard to the information they require, you should check their requirements before applying for a certificate.

CSS (Cascading Style Sheets)
A style sheet programming language that describes how a document, often written for the web in HTML, should appear.

A daemon is a type of program on Unix-like operating systems that runs unobtrusively in the background, rather than under the direct control of a user, waiting to be activated by the occurance of a specific event or condition.

Data Center
A facility used to house servers. A data center is a safe place to keep a server as it includes backup power supplies, multiple communication connections, and environmental controls.

Dedicated IP Address
A dedicated IP address is different from a shared IP address in that only one cPanel account is assigned to it. A dedicated IP address is needed to install an SSL certificate. There is no SEO benefit or performance difference between a shared and dedicated IP address.

Default Address
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 feature that is no longer supported.

DHA (Directory Harvest Attack)
A technique employed by spammers whereby they attempt to find valid email addresses through guesswork, using various permutations of common addresses.

Dictionary Attack
A method whereby a malicious user tries to guess a password using words found in a dictionary. Similar to a Brute Force Attack.

Directory (Folder)
A repository for files, analogous to a file folder on a personal computer. In website management, a directory will contain the website's files.

Disk Space Quota
A limit placed on the amount of disk space an account is allowed to use.

DKIM (Domain Keys Identified Mail)
The replacement for the older DomainKeys protocol. Like DomainKeys, DKIM attempts to verify the origins of email messages.

DNS (Domain Name System)
The component of the Internet that acts as a "phone book," converting human-readable domain names (such as into computer-readable IP addresses (such as

DNS Zone
An administrative space or portion of the Domain Name System. This space is responsible for directing web traffic to the correct location. An example is, a DNS zone whose servers direct its web traffic.

DNS Zone File
A file on the server that primarily maps IP addresses to domain names. A correctly configured zone file must exist in order for visitors to access your website from the Internet.

The name a site owner gives a website, which will appear in the website's URL and email addresses. Usually seen as, where example is meant for the domain name.

Domain Forwarding
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 by typing

A deprecated email authentication method that attempts to verify that a message actually came from the domain it appears to have come from.

The process of transferring data from a remote computer to a local computer. When you copy a file from a computer on the Internet to your computer, you are "downloading" that file.

Email (Electronic Mail)
Internet. Email can also be sent to a large number of addresses at once through a Mailing List.

An option for handling mail received by the default or catch-all email address for a cPanel account. The fail option returns all mail received by the default address as undeliverable.

FAQ (Frequently Asked Questions)
An FAQ is a document that lists and answers the most common questions on a particular subject. It is considered good netiquette (the Internet's code of conduct) to check for FAQs and read them.

A combination of hardware and software that separates a LAN into two or more parts for security purposes. A firewall is commonly used to separate a network from the Internet.

A tool that lets you forward a copy of every email message you receive to another address. When a forwarder is set up, you will still receive mail at the original recipient address. If, however, you create a forwarder without first creating the original address, messages will be forwarded to the end address without being sent to the original address, as it does not exist.

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 two dots. FQDNs must be written in lowercase letters.

FTP (File Transfer Protocol)
A method of transferring files from one computer to another. cPanel 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. It is highly recommended that clients disable FTP, which can be done using the "Disable FTP Access" feature in cPanel, and use a secure protocol, such as SCP or SFTP.

A thousand (technically 2^10 or 1024) Megabytes.

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 .gz. The gzip is often used with tar to create a "tarball" file (which ends with .tar.gz).

Home Directory
A cPanel account's highest-level directory that 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 public_html directory. The exception to this is if you create an Addon or Sub Domain and set the Document Root outside the public_html directory.

The unique, human recognizable name by which a server will be known across the Internet. For example, Please note that a server's hostname is distinct from your domain name.

A file that resides in a specific directory, and contains configuration information applying to that directory. The .htaccess file may also contain authentication instructions.

HTML (Hypertext Markup Language)
The language in which most pages on the World Wide Web (WWW) are written.

A file that resides in a specific directory, along with an .htaccess file. The .htpasswd file contains encrypted password information when authentication has been set up for the directory.

HTTP (Hypertext Transfer Protocol)
The method (protocol) for transferring data over the internet. This requires a HTTP client program on one end and a HTTP server program on the other end. HTTP is the most important protocol used on the internet.

The configuration file for the Apache web server. More information about httpd.conf can be found here.

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.

Index Page
The page, most often titled index.php or index.html, 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.

Internet Media Type
Previously called a MIME (Multipurpose Internet Mail Extensions) Type, this component of a file identifies the file type, so that web browsers know how to handle it.

ionCube is a loader that protects the intellectual property of software developers who produce software written in PHP. The Zend Guard Loader is another tool that can encode and decode PHP scripts. Both of these loaders are installed by default.

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. It is a unique number consisting of 4 parts separated by dots. 123.45.678.9 could be an IP number. Every machine that is on the Internet has a unique IP number.

A network-oriented programming language invented by Sun Microsystems specifically designed for creating programs that can be downloaded to your computer from a web page and immediately run. Using small Java programs ("applets"), Web pages can include features such as animations, calculators and other fancy or interactive tricks.

JavaScript is a scripting language based on the concept of prototype-based programming. The language is best known for its use in websites as client-side JavaScript. It is distantly related to Java, with their main similarity being the C programming syntax.

A central component of the server's operating system. The kernel manages communications between the user and the server's resources, such as its processor and the memory.

List Server
The most common kind of mailing list. List servers originated on BITNET, but are now common on the Internet.

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 of errors generated by Apache that visitors have encountered on a website.

The user- or account-name used to gain access to a computer system. Also, the act of entering or "signing on" to a computer system.

Message Transfer Agent
A program responsible for sending and receiving email messages. Also known as a Mail Transfer Agent (MTA) or Mail Relay.

MIME (Multipurpose Internet Mail Extensions)
The Internet standard for attaching non-text files to standard email messages. Non-text files can include graphics, spreadsheets, word-processor documents, sound files, etc. An email program is said to be "MIME Compliant" if it can both send and receive files using the MIME standard.

To "mirror" something is to maintain an exact copy of it. The most common use of the term on the Internet refers to "mirror sites" which are FTP or web sites that maintain exact copies of material originally stored at another location. Another common use of the term "mirror" refers to writing information to more than one hard disk simultaneously to prevent its loss or destruction.

In encryption algorithms such as RSA, the modulus is the number that both the private and public keys have in common. You can view a key's modulus using the "SSL Key Manager" feature in cPanel.

MX Records
A record that specifies where email should be sent for a domain, as it contains the mail server's IP address. When using a third-party email service or custom mail delivery, you may need to change the MX record for a domain using the "MX Records" feature in cPanel. There are other methods for forwarding messages from a domain to a mail server, but MX Records are the preferred method.

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 shopping carts, bulletin boards, and blogs. cPanel provides an integrated MySQL interface as well as a MySQL database editing tool called phpMyAdmin.

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 (or propagate) all the nameservers on the Internet. Example of nameservers are and

The desired mode of manners and conduct for the Internet.

A network is created any time 2 or more computers are connected together to share resources. When 2 or more networks are connected, it becomes an internet.

NIC(1) (Networked Information Center)
Any office that handles information for a network can be referred to as an NIC. The most famous of these is the InterNIC, the original office of domain registration. (Another definition of NIC is Network Interface Card, which plugs into a computer and adapts the network interface to the appropriate standard.)

NIC(2) (Network Information Center)
A unique ID Code issued by to identify contact persons associated with a domain name. There can be up to 3 NIC handles per domain, referred to as 'ADMIN / TECH / BILL', each having its own area of responsibility.

When someone or something is connected to the Internet, they are considered "online".

Parked Domain
A second domain that points to a primary domain. When users attempt to access the parked domain, they will see the main website. For example, both and go to the same place, as is a parked domain for Parked domains must be registered with a domain registrar and configured to point to our servers to properly function.

A code used to gain access to a locked system. Effective passwords should contain both letters and non-letters and not be common or easily guessed words (such as address, DOB or pets' names).

PASV (Passive Mode)
A mode for FTP connections that will initiate connections from the client side. Using this mode may be helpful if a user is having problems connecting to an FTP server through a firewall.

PEAR (PHP Extension and Application Repository)
A repository of PHP code. You can use the "PHP Extension Manager" feature in cPanel to search for and install PEAR packages consisting of PHP programs which can perform useful functions for your website.

Known for its ability to process text, Perl is a useful language for web applications. Perl applications are commonly found as .pl, .pm, and .cgi files and may require Perl modules. More information about Perl can be found here.

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 extension .php. Some PHP applications require PEAR packages, which can be installed through the "PHP Extension Manager" feature in cPanel. More information about PHP can be found here.

PHP Package
A piece of software written in the PHP language.

A graphical application that allows website administrators to manipulate and manage MySQL databases over the Internet. Full documentation for phpMyAdmin can be found here.

PID (Process ID)
A unique number that your server assigns to each process that runs.

A program for determining if another computer is presently connected to the Internet.

Shorthand for "picture element", a pixel is the smallest unit of resolution on a monitor. It is commonly used as a unit of measurement.

A small piece of software that adds features to a larger software application. Common plug-ins are those for web browsers or graphic programs.

POP (Point Of Presence/Post Office Protocol)
A Point of Presence usually refers to a city or location where a network can be connected to. For example, if an Internet company says they have a POP in Vancouver, this means they have a local telephone number in Vancouver and/or a place where leased lines can connect to their network. A second definition, Post Office Protocol, refers to the way email software (such as Eudora) retrieves mail from a mail server. Almost all SLIP, PPP or shell accounts come with a POP account as well.

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.

First and most frequently, a port is where information goes into and/or out of a computer, such as the serial port on a PC. Secondly, a "port" often refers to the number appearing after the colon (:) in a domain name, such as Thirdly, to "port" something refers to translating a piece of software from one computer platform to another (for example, from Windows to Macintosh).

POSIX (Portable Operating System Interface)
A standardized collection of commands for the Linux operating system.

A single message entered into a blog, newsgroup, mailing list, or other communications system.

An instance of a program running on the server.

The time during which your DNS Zone information spreads across the internet to servers that didn't know about it before. Propagation takes two forms, changes to your DNS Zone and changes to your WHOIS information. The WHOIS is the master record that tells every DNS Server in the world which is the authoritative server for your domain. A change to your WHOIS information (done at our/your domain registrar) can take up to 72 hours to propagate fully. A change to your DNS Zone information typically affects only a handful of servers, and so is done much more quickly.

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 www directory is a symbolic link (or shortcut) to public_html. Any files and folders inside of public_html are visible over the Internet, unless the website owner specifically protects them with password protection or using the .htaccess file or "Password Protection" feature in cPanel.

A programming language which is used for many applications. More information about Python can be found here.

A feature that sends users to a different domain than the one they were trying to access. For example, a user may reach by typing You can setup temporary or permanent redirects using the "Redirect Manager" feature in cPanel.

A web page that 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."

Regular Expressions
Often seen as regex or regexp, regular expressions are a means of formatting text so that a specified program can process it, using it to search in a prescribed way. A wildcard character, such as an asterisk, is an example of a regular expression.

A program that automatically searches the WWW for files and catalogues the results.

Root Directory
The highest level directory on a server, usually notated by a forward slash.

A webmail client that allows users to check email through an Internet browser rather than an email client.

An algorithm for generating public and private keys when sending encrypted data between a local machine and a remote machine. The name of this method is not an abbreviation; it is named after its three inventors.

RTFM (Read The F***ing Manual)
A commonly used abbreviation in online forums and email, in response to foolish questions or questions already answered in the FAQ. In expurgated texts, substitutions such as "read the flaming manual", "read the fine manual" or "read the friendly manual" are used.

SCP (Secure Copy Protocol)
A method of transferring encrypted files from one computer to another. This method prevents data from being intercepted and read. This secure protocol is preferred over FTP.

Search Engine
A tool for locating information on the Internet by topic. Popular search engines include Google, Yahoo and Bing.

SEO (Search Engine Optimization)
The methods used to boost the ranking or frequency of a website in results returned by a search engine, in an effort to maximize user traffic to the site.

Software that allows a user to interact with a server. Many 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.

Unsolicited email sent in bulk, usually by an automated system or exploited web application.

SPF (Sender Policy Framework)
A feature that allows a recipient server to verify that an email message has really been sent from the domain specified in the From: field. Enabling SPF can prevent your server from receiving replies to spam that has forged your domain name as part of the sender's address. SPF only works if both the sending and receiving mail servers have SPF enabled.

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.

SQL (Structured Query Language)
A specialized programming language for sending queries to databases. Each application will have its own version of SQL-implementing features unique to that application, but all SQL-capable databases will support a common subset of SQL.

SQL Database
A type of relational database management system

SSH (Secure Shell)
A network protocol that allows a user to log into a remote machine securely. You can create keys for authenticating a user's identity during SSH login through the "Manage SSH Keys" feature in cPanel.

SSL (Secure Sockets Layer)
A cryptographic scheme that allows 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. Website owners can install an SSL certificate on a website (via the "Install SSL Certificate" feature in cPanel) to allow the site to be protected by SSL.

SSL Certificate
An electronic document (using the filename extension .crt) 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 sub domain URL would appear as

To become a member of a mailing list, newsgroup, or other online service.

A feature provided by Apache that allows users to run CGI and SSI applications on the system as themselves. By default, CGI and SSI are executed using the system account known as nobody with the UID of 99.

Sysop (SYStem OPerator)
Someone responsible for the physical operations of a computer system or network. A System Administrator (or Sysadmin) decides how often system maintenance should be performed, and the Sysop performs those tasks.

Originally derived from "Tape Archive," a program that collates files for transfer or distribution on UNIX computers. Files processed by this method are usually compressed, commonly called "tarballs," and use the filename extension .tar. Due to the compression commonly used, .tar often precedes the .gz file extension.

A file collated by the tar program, and usually compressed.

A thousand (technically 2^10 or 1024) Gigabytes.

An ongoing message-based conversation on a single subject.

TTL (Time To Live)
Specifies how long a particular record should be kept in memory before it should be deleted. This is most often used within DNS.

UID (User ID)
The unique user number that any user on your server will be assigned during a session.

The most common operating system for servers on the Internet.

The process of transferring data from a local computer to a remote computer. When you copy a file from your computer to a computer on the Internet, you are "uploading" that file.

URI (Universal Resource Identifier)
On the web, a URI is a string of characters that identifies a website. URI is often used synonymously with the terms "URL" and "web address," although there are technical differences among the three.

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 than URL is often used synonymously with the terms "URI" and "web address," although there are technical differences among the three.

User Session
The session of activity that a user with a unique IP address spends on a web site during a specified period of time.

Also called login name, logon name, sign-in name, sign-on name. a unique sequence of characters used to identify a user and allow access to a computer system, computer network, or online account.

A person who views your website.

Web Browser
An application used to view and interact with sites and pages on the World Wide Web, such as Chrome, Firefox, Internet Explorer, and Opera.

Web Developer
A person or company that develops internet software applications, or that creates and maintains websites.

Web Root
The top-most directory of your website (namely, public_html or www), inside which all of the files and subdirectories for your website reside. Also known as the document root.

Web Server
A program, such as Apache or LiteSpeed, which receives requests from clients (web browsers), retrieves the requested web pages, and "serves" them to the clients.

Any application which allows website owners to access email through a web browser. The main advantage of 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.

a person who designs or maintains a website.

WHM (WebHost Manager)
Companion software to cPanel, designed for web hosting companies and system administrators.

An Internet directory service for finding out who owns a domain.

A compressed file format (.zip). Many files available on the Internet are compressed or "zipped" in order to reduce storage space and transfer times.

A DNS Zone, an administrative space or portion of the Domain Name System. This space is responsible for directing web traffic to the correct location. An example is, a DNS zone whose servers direct its web traffic.

Zone File
A file on the server that primarily maps IP addresses to domain names. A correctly configured zone file must exist in order for visitors to access the server from the Internet.
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