WHM Glossary

For WHM version 11.24

“A” (Address) Entry: A record, residing on your server, that contains your server’s hostname and IP address. The “A” entry is essential because it tells DNS servers the identity of your server, allowing visitors to find your server on the Internet.

ACLs (Account Creation Limits): When you create reseller accounts in WHM, these are the constraints you place on the resellers’ privileges.

Addon Domain: An additional domain name associated with your cPanel account. Each addon domain is stored in its own directory which you can configure. This allows you to manage multiple domains from a single cPanel account. Addon domains must be registered with a domain name registrar to work.

Addons (cPAddons): Additional services, usually provided by cPanel, for your users. Some examples of addons are blogs, message boards, and shopping carts.

AIM (AOL Instant Messenger): A widely used instant messaging program. WHM can notify you via AIM if there is a problem with your server. More information about AIM can be found at http://dashboard.aim.com/aim.

Analog: 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/.

Anonymous FTP: 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 you wish 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.

Apache: 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.

ASCII (American Standard Code for Information Interchange): A common character set based on the English alphabet.

atd: A daemon for the at command in Linux operating systems, which performs scheduled tasks. This daemon is disabled by the WHM Quick Security Scan feature.

Authentication: A process for confirming the identity of someone with whom you want to share information. On the web, authentication usually involves either a username and password set or a public/private key pair.

Autoconfig: A process that sets up a user’s Outlook® or Outlook Express account to receive their cPanel email. You can enable or disable this feature using WHM's Enable/Disable Outlook® Autoconfig? feature.

AWStats: A program that provides information about the visitors to your website in both graphical and statistical views. More information about AWStats can be found at its website: http://awstats.sourceforge.net/.

Bandmin: An application that records and logs bandwidth usage for domains on your server. You can view this information by accessing yourdomain.com/bandwidth/.

Bandwidth: The amount of data transferred to and from a web 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. You may wish to limit your users’ bandwidth, as it can affect the performance of your server.

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

BIND (Berkeley Internet Name Domain): The most prominently used DNS server software. Also referred to as named.

Blackhole: An option for handling mail received by the default or catch-all email addresses of cPanel users. The “blackhole” option discards mail after it is accepted; for this reason, it can result in more spam being sent to your users, and it places a larger load on your server than the “fail” option.

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

BoxTrapper: 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.

BoxTrapper Blacklist: 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.

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.

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. WHM includes cPHulk, a protection system that lets you lock out brute force attackers after a specified number of failed attempts.

Build: A minor version of cPanel. Builds exist in 4 types which are, in order from least to most stable, EDGE, CURRENT, RELEASE, and STABLE. Please visit our installation documentation for an in-depth look at each build type.

CA (Certificate Authority) Bundle: A file on your server that verifies that your public and private keys were issued by a trusted entity. If your Certificate Authority sent you a CA bundle file, you can install it to your server using WHM’s Install a SSL Certificate and Setup the Domain feature, or the Manage Service SSL Certificates feature.

Cache: A stored piece of information to which the server refers instead of accessing the information source, to save bandwidth and time. In WHM, you can configure caching of DNS records using the Edit DNS Zone feature. You can configure caching of disk usage data via the Tweak Settings page.

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

Catch-All Address: The email address to which cPanel & WHM routes any email message sent to email accounts which do not exist at your domain. Also known as a Default Address.

Certificate (Public Key Certificate): 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 Signing Request (CSR): A request for a certificate sent by a server’s administrator to a certificate authority.

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

CGI Script Alias: A feature of Apache that creates a directory named cgi-bin. This is a special directory containing files which Apache knows to execute as CGI scripts.

Character Set: (Also sometimes known as “charset.”) A code that pairs a sequence of characters with a set of numbers, allowing a computer to store and transmit the characters. ASCII is one popular character set; several character sets exist for Cyrillic and Asian alphabets. For more information visit http://en.wikipedia.org/wiki/Character_set.

chmod (change mode): A CLI command that allows you to set permissions to view, write, or execute a script.

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 operating a computer in a text based environment.

Cluster: A group of linked servers. WHM allows you to create a DNS cluster, which keeps DNS records synchronized among a group of computers, eliminating the need for manual updates to be made to each server.

Compiler: A computer program that translates source code written by people into a language readable by a computer. WHM allows you to disable your web server’s compilers for most users, as a security measure.

Courier: Mail server software, known for its IMAP component. More information can be found at http://www.courier-mta.org.

cPAddons: Pieces of software that you can install on your website through cPanel. cPAddons provide useful tools to your website. Common examples include bulletin boards, chat programs, and online shopping carts.

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

cPanel: Companion software to WHM, designed to simplify website maintenance for website owners.

cPanel Packages: Pieces of software that are bundled together for archiving and installation. cPanel packages, such as FTP and MySQL software, can be updated using the WHM Update Config feature.

cpdavd: The cPanel daemon that provides access to the Web Disk feature.

cplog: Also known as error_log, a file that contains a record of errors encountered by the Apache web server. This file can be found at /usr/local/apache/logs/error_log.

cpmove: A copy of a user’s website created by running a script called pkgaccount. The cpmove file is useful as a backup and can be manually uploaded to restore the user’s web files.

cpsrvd: cPanel Service Daemon, the software that runs cPanel on your server.

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

.crt 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.

cupsd: Common Unix Printing System Daemon, used by the web server for printing. This daemon is disabled by the WHM Quick Security Scan feature. We strongly suggest disabling cupsd as it is vulnerable to attacks.

Daemon: A computer program that runs as a background process, rather than being visible to, and directly controlled by, the user.

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

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

Deprecated: A term used to describe a feature which is no longer supported.

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 your personal computer. In website management, a directory will contain your web files.

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

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

DNS (Domain Name System): The component of the Internet which acts as a “phone book,” converting human-readable domain names (such as www.example.com) into computer-readable IP addresses (such as, in the case of example.com).

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 example.com, a DNS zone whose servers direct its web traffic.

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

dnsadmin: A set of programs that helps manage DNS information. More information can be found at here.

Domain: The name a user gives a website, which will appear in the website’s URL and email addresses. Usually seen as example.com, 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 example.com by typing example2.com. See also redirect.

Dovecot: Mail server software designed for optimal security. More information can be found at http://www.dovecot.org.

EIDE: Enhanced IDE (integrated drive electronics). A method for connecting hardware to a computer. WHM’s Optimize EIDE Hard Drives? feature can speed up communications between your server and external hard drives connected by EIDE.

Environment Variables: Values that advanced administrators place within specific files on the server to change the behavior of Apache and PHP. (For information on configuring environment variables, click here.)

Exim: Mail server software, known for its configurable nature. More information can be found at http://www.exim.org.

Fail: An option for handling mail received by the default or catch-all email addresses of cPanel users. The fail option returns as undeliverable all mail received by the default address.

Forceful Reboot: 1 of 2 methods for restarting your server. This forces the server to restart regardless of what error(s) if may have encountered. You should only use a forceful reboot if you cannot reboot gracefully, as it may case data loss.

FormMail Clone: A piece of software that imitates the function of FormMail. FormMail is used to create an email message from data that a user enters into the text fields on a web page, and send the message to the intended recipient.

FrontPage®: A Microsoft® application that allows you to edit your 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 users 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. WHM and cPanel come equipped with FTP servers that can be configured to your preference. An FTP client must be installed on your 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®).

FQDN (Fully Qualified Domain Name): A name that uniquely defines a domain’s location. It is usually seen as host.example.com. 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.

Gem: A piece of software in the Ruby language. The central repository for these pieces of software is called RubyGems. For more information, see http://rubyforge.org/projects/rubygems.

Generators (web stats): Pieces of software that will compile statistics for your web server. For example, they can tell you how much bandwidth has been transferred per domain. 3 generators can be configured through WHM: Analog, AWStats, and the Webalizer.

Graceful Reboot: The preferred way to restart your server. This method stores new system information before shutting down.

gzip: 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. In Unix and Linux systems, 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, 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 public_html directory or a subdirectory of public_html.

Hook Scripts: A program that is triggered by some event. WHM allows you to embed custom hook scripts into the Apache configuration process using the EasyApache (Apache Update)? feature.

Horde Webmail: A webmail client that is included with WHM. A webmail client allows users to check email through a web browser.

Hostname: The unique, human recognizable name by which a server will be known across the Internet. For example, host.example.com. You can specify or change your server’s hostname using WHM’s Hostname feature. Please note that the server hostname is distinct from your domain name.

.htaccess: 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 are written. See also CSS.

httpd.conf: The configuration file for the Apache web server. For more information, visit http://httpd.apache.org/docs/2.2/configuring.html.

ICQ: An instant messaging service. You may choose to receive updates from your server via ICQ. For more information, visit http://www.icq.com.

IMAP (Internet Message Access Protocol): Along with POP3, one of the two most widely used email transfer methods.

Include (file): A file that is automatically included within another file by the program reading it. In WHM, includes pertain to a series of specifications that can be added to your Apache configuration file (httpd.conf) through the include command.

Index Page: The page 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.

Interchange: A full-featured e-commerce application server that will allow you to conduct business online, granting your users a virtual shopping cart, payment method, and more.

IonCube: A loader that, if enabled, cPanel can use for loading PHP. For more information on IonCube, visit http://www.ioncube.com.

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.

IRC (Internet Relay Chat): A method of real-time online communication that allows both group discussion and one-to-one messaging, as well as data transfer.

Jailshell: A CLI configuration that restricts users’ access rights by partitioning the system into smaller parts. This will prevent a user from leaving his or her user directory, restricting access to the file system and some commands.

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

Key: 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 .key.

Loader: The part of a system that loads a program. In WHM, you can use the Tweak Settings screen to choose the loader that cPanel uses for PHP.

Log: 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.

Log Files (see also the definition of Log, above):

  • access_log — A file containing a record of IP addresses of visitors that have accessed sites hosted by your server. This file can be found at /usr/local/apache/logs/access_log.
  • cpdavd_error_log — A file that contains a record of errors that were encountered by cpdavd. This file can be found at /usr/local/cpanel/logs/cpdavd_error_log.
  • cphulkd_errors_log — A file that contains a record of errors encountered by the cPHulk daemon, cphulkd. This file can be found at /usr/local/cpanel/logs/cphulkd_errors.log.
  • error_log — A file that contains a record of errors encountered by the Apache web server. This file can be found at /usr/local/apache/logs/error_log.
  • license_log — A file that contains a record of errors that were encountered when cPanel checked its license. This can be found at /usr/local/cpanel/logs/license_log.
  • login_log — A file that contains a record of failed login attempts. This file can be found at /usr/local/cpanel/logs/login_log.
  • stats_log — A file that contains a record of the activities of cpanellogd, the daemon that compiles your server’s web statistics. This file can be found at /usr/local/cpanel/logs/stats_log.
  • tailwatchd_log — A file that contains a record of errors encountered by tailwatchd, the daemon that monitors your server’s logs. This can be found at /usr/local/cpanel/logs/tailwatchd_log.

Local User: A user accessing a service on the machine on which the service is located, as opposed to remotely. When you select this option from the Tweak Settings feature, it lets a cPanel user set up an email address that will receive any mail sent to an invalid address at his domain.

Mailing Lists: A list of email accounts that can be mailed simultaneously using one account name. Also see Mailman.

Mailman: Mailing list software; Mailman sends email to a group of specified email addresses. For more information, visit http://www.list.org.

Maildir: A format for storing email wherein individual messages are stored with unique filenames. Maildir is rapidly becoming the standard mail storage format. We recommend using Maildir. See also mbox.

mbox: A format for storing email wherein messages are kept in a single file. This method is outdated and is not recommended. See also Maildir.

Modulus: In encryption algorithms such as RSA, the modulus is the number that both the private and public keys have in common. The plural of modulus is moduli. You can view a key’s modulus using the SSL Key/Crt Manager feature.

mod_userdir: A feature of Apache that lets visitors view websites on your server by typing your hostname followed by a tilde and the website owner’s username. (Example: http://host.example.com/~username) Disabling this via the WHM Security Center? is desirable, as the bandwidth used when the site is accessed using this method is attributed to the web host’s main domain, skipping bandwidth monitoring systems. For more information on mod_userdir, you should visit http://httpd.apache.org/docs/2.0/mod/mod_userdir.html.

Mount: In general computing, this is the act of making the file system accessible to users. In a Unix or Linux operating system, mount can be used as a command to tell the operating system that a file system or device is ready to use and to affix that system or device to a certain directory.

MRTG (Multi Router Traffic Grapher): Software that allows you to monitor network traffic. For more information, visit the MRTG website.

MySQL: This term refers to a database management tool, as well as the type of database it manages. Such databases are integral to applications like bulletin boards and retail shopping. WHM lets you manage MySQL database services via the SQL Services section.

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. If you are using an email scanning service or custom mail delivery, you may need to change the MX record for your domain using the Edit MX Entry feature.

named: The most prominently used DNS server software on the Web. Also referred to as “BIND.”

Nameserver: 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 you to find where a domain is located. Nameservers gather 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”).

nis (Network Information Service): A directory protocol for distributing information across or within networks. This daemon is disabled by the WHM Quick Security Scan feature.

NFS (Network File System): Allows users to access remote files as though the hardware they are accessing to manipulate the file was attached directly to the local machine. This daemon is disabled by the WHM Quick Security Scan feature.

nfs statd: A process used for NFS file system mounting. This daemon is disabled by the WHM Quick Security Scan feature.

Nobody: This is a Unix or Linux system account with the UID of 99. This system account is used to execute CGI and PHP scripts if SuEXEC and PHPSuEXEC are disabled.

nsd: DNS server daemon. More information can be found at http://www.nlnetlabs.nl/projects/nsd/.

open_basedir: A feature that uses PHP to prevent users from opening files outside their home directories. This can be enabled using WHM’s Tweak PHP Security feature.

Open Relay: A mail server configuration that allows anyone to send mail through the server. For security reasons, allowing your server to operate as an open relay is strongly discouraged.

Option Module (“opt mod”): An Apache configuration option that advanced administrators can add to the EasyApache (Apache Update)? interface.


  1. A set of resource limits assigned to a user’s account. You can create, edit, and delete packages using the WHM Packages feature.
  2. Pieces of software that are bundled together for archiving and installation. cPanel packages, such as FTP and MySQL software, can be updated using the Update Config feature.

Parked Domain: A second domain that points to your primary domain. When users attempt to access the parked domain, they will see your main website. For example, both http://www.cpanel.net and http://www.cpanel.com go to the same place, as cpanel.com is a parked domain for cpanel.net.

Passive Mode (PASSV): 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.

Perl: 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. Perl modules can be installed using the WHM Install a Perl Module feature.

Perl Module: A piece of software written in the Perl language.

PHP: A computer scripting language in which many web-based applications are written. PHP applications are commonly found with the filename extensions .php, .php4, or .php5. Some PHP applications require PEAR packages, which can be installed in WHM through the Module Installers feature.

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

PECL (PHP Extension Community Library): A repository for C extensions (pieces of software) designed for use in PHP. For more information, see the PECL website.

phpMyAdmin: An application that allows you to manipulate and manage MySQL databases over the Internet.

PHPSuexec: Like suEXEC for CGI, PHPSuexec allows users to execute PHP code under their own user ID. By default, PHP is executed using the system account known as nobody with the UID of 99.

POP before SMTP: An authentication method for mail servers that will allow a user who has received mail via POP3 or IMAP to send mail for 30 minutes without reauthenticating through SMTP.

POP3 (Post Office Protocol version 3): Along with IMAP, 1 of the 2 most widely used email transfer methods. POP3 simply copies every message in your email account to your local computer, removing it from the mail server. No information is sent back to your email account about message replies, forwarding, etc. If you use multiple computers to check your email, it is advised that you use IMAP instead of POP3.

Portmap: A service that maps program numbers to network addresses on a server. Often seen as rpc.portmap or portmap. This service is not widely used; it is disabled by the Quick Security Scan feature.

PostgreSQL: A database management system, much like MySQL. For more information, see the PostgreSQL website.

Process: An instance of a program running on your machine.

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

ProFTPd: One of 2 FTP servers included in your installation of WHM. (The other is Pure-FTPd.) More information can be found at http://www.proftpd.org.

Propagation: The spread of a website’s DNS information across the Internet.

Proxy: Short for a proxy server. This server receives requests from users and forwards those requests to other servers.

public_html: The subdirectory, located inside a user’s home directory, that holds the files that make up a website. The www directory is a link to public_html. Any files and folders inside of public_html are visible over the Internet, unless the domain owner specifically protects them with a password.

Pure-FTPd: One of 2 FTP servers included in your installation of WHM. (The other is ProFTPd.) More information can be found at http://www.pureftpd.org.

Python: A programming language which is used for many applications. When you encounter this term under Update Config, it refers to the Python interpreter, which must be installed on your server before it can run Python programs. More information can be found at http://www.python.org.

Quotas: Limits to the amount of disk space a user is allowed to take up. In order to set up quotas for your users, you must first use WHM’s Initial Quota Setup feature.

Raw Opts: (Also known as “custom configure flags.”) Lines of data that advanced users can add to a specific file on the server in order to customize the configuration of Apache. (For more information on configuring raw opts, click here.)

RBL (Realtime Blackhole List): A list of mail servers known to send spam. You are able to subscribe to the list and block incoming mail from such mail servers using the WHM Exim Configuration Editor.

Redirect: To send users who access a domain to another domain. For example, a user may reach example.com by typing example2.com. See also domain forwarding.

Reseller: In web hosting, resellers take a large amount of resources (bandwidth and disk space) on your server and sell those resources in smaller packages to individual cPanel account holders.

Referer: A web page which links to your 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 * is an example of a regular expression.

Relayer: A user who forwards email to a secondary destination. WHM’s View Relayers feature lets you view users on your server who have relayed mail.

Resolver: The client side of the DNS system. Resolvers are programs that process DNS queries, working to obtain an IP address from a human-recognizable URL. In Unix and Linux, the file /etc/resolv.conf usually points to a server’s resolvers.

Rollback: In computing, a rollback involves restoring any part of a system to a previous configuration.

Root: Specific to Unix and Unix-based systems. A computer account, used by a system administrator, which carries full privileges for configuring a computer system. Also called “superuser.”

Root Language File: A file that supplies wording for your cPanel interface when a needed term in the interface is missing from the primary language files. The root language file is located in the directory /usr/local/cpanel/lang. The primary language files are located in directories specific to their themes; for example, /usr/local/cpanel/base/frontend/x3/lang.

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

RPM: The Red Hat® Package Manager. “RPM” can refer to either the file format or the software packaged within that format.

RubyGems: A package manager and program library for the Ruby programming language. Also see Gem. For more information about RubyGems, visit http://rubyforge.org/projects/rubygems/.

/server-info and /server-status: These pages contain general information about the server. You can use the Tweak Settings screen to configure which users are allowed to view this information.

Service Manager: In computing, a piece of software that monitors processes and services on a machine. WHM’s Service Manager feature lets you enable and disable services.

Shell: Software that allows you to interact with a computer. Many Unix shells allow you to type commands, and are often referred to as CLIs, or command line interfaces.

Shell Fork Bomb (Protection): A shell fork bomb is a malicious process that creates a cascade of new processes in order to use a server’s system resources, in effect, crashing the server. WHM offers a protective service from shell fork bombs.

Shopping Cart: A piece of software used on web servers during e-commerce. A shopping cart allows the shopper to hold items they wish to purchase while they are still shopping on the website.

Skeleton Directory: A directory that defines what files and subdirectories new accounts will have by default. When the account is created, the new user’s account will contain an exact copy of the skeleton directory.

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.

Spam: 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 and BoxTrapper that can cut down on the amount of spam received. You can use the Tweak Settings screen to enable these services for your users.

SpamAssassin: An application which can filter suspected spam before you receive it. SpamAssassin can be configured to filter spam more or less aggressively, according to your needs. Learn more about SpamAssassin at http://spamassassin.apache.org. You can use the Tweak Settings screen to enable this service for your users.

Spoof: An attack wherein the attacker conceals his identity by appearing as another user through the falsification of data, such as email headers.

Sprite: A type of file that can incorporate several different images. Sprites are used to speed up the load time of the cPanel interface. When you add an icon, cPanel will add it to the appropriate sprite file. If your icon is not displayed properly, clicking Generate Sprites in the Branding Editor can cause the sprite file to upload properly.

SourceGuardian/OldSource Guardian: PHP loaders that utilize a binary bytecode and, sometimes, multiple levels of encryption. For more information visit http://www.sourceguardian.com. You can use the Tweak Settings screen to select a PHP loader.

SQL Database: A type of relational database management system. WHM is compatible with both MySQL and PostgreSQL.

SquirrelMail Webmail: A webmail client that allows a user to check his or her email through an Internet browser.

SSH (Secure Shell Handler): A network protocol that allows a user to log into a remote machine securely. WHM can create keys for authenticating your identity during SSH login, and lets you manage SSH keys via the Manage SSH Keys feature.

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.

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. You can install an SSL certificate via the Install a SSL Certificate and Setup the Domain feature.

Stunnel: A free program that is used to provide universal SSL/TLS tunneling services. A tunneling service allows computers to communicate with each other directly using SSL/TLS protocols.

Style: Also known as a “skin,” the style contains the graphics that determine the “look and feel” of a user’s cPanel interface.

Subdomain: A subsection of your website that exists as a subdirectory in your home folder. If your domain were example.com, then the subdomain URL would appear as subdomain.example.com.

suEXEC: 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.

Theme: In cPanel software, the theme is the larger, skeletal frame work to which the style or ‘skin’ will be applied.

Time to Live: Often abbreviated as TTL, it specifies how long a particular record should be kept in memory before it should be deleted. This is most often used within DNS.

Tooltip: A small box of information that will hover above an icon when the cursor points at it. This is common through cPanel and WHM as well as many other GUIs. In the WHM Languages interface, this term defines the language of the text within the tooltip information box.

Trojan Horse: Also known simply as a trojan, a piece of software that claims to perform one function but actually performs malicious functions secretly.

Trust Key Relationship: A cryptographic scheme involving a public and private key pair.

Unix Time: Unix time is measured by the number of seconds that have passed since the 1st of January, 1970 UTC.

Urchin: A web statistics analysis program made by Google. For more information, see the Urchin website.

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

  • 99 — nobody — Default executor of CGI scripts if suEXEC is disabled.
  • 0 — root — The top-level system user.
  • note Note: UIDs 0 through 100 are reserved for system accounts such as admin and root.

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

VirtualHost: A method of hosting multiple domains on a single server and sometimes on a single IP address. To learn about the types of virtual hosting, visit http://en.wikipedia.org/wiki/Virtual_host.

Webalizer, The: A program that displays various statistics for your website using tables and graphs. Full documentation for The Webalizer can be found at its creators’ website: http://www.webalizer.com.

Webmail: Any application which allows you to access your email through a web browser. The main advantage to webmail is the ability to access your email account from any computer connected to the Internet without having to install or configure a specific mail program.

Web Disk: A feature of cPanel that lets you manipulate your web files by dragging and dropping, just as you do on your local computer’s operating system.

Wheel Group: This group of users is allowed to execute the su or su- command on a Unix-based system, which allows them to become the root user. This command requires the password for the root user.

WHOIS: A Unix/Linux command that can be executed in a terminal session in order to find out who owns a domain. For example, whois cpanel.net will return the ownership information for cPanel.

X-source Headers: Pieces of information added to email messages sent from a PHP script on your server, detailing the script’s location. Enabling these headers can help you locate insecure email scripts being abused by spammers. You can enable these headers using the Tweak Settings feature.

XSRF Attack (Also, CSRF): XSRF and CSRF stand for Cross-Site Request Forgery. This attack exploits a trusted website by forcing a user to execute unauthorized commands, usually through a hyperlink. To help prevent XSRF attacks, you can use Tweak Settings to limit the functions that cPanel and WHM perform by requiring that each request come from a domain or IP on your server.

Zone: 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 example.com, a DNS zone whose servers direct its web traffic.

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

Topic revision: r18 - 13 Nov 2012 - 19:23:08 - Main.LaurenceSimon