WordPress Glossary

Administrator user role

A WordPress user role which allows the user privileges: activate, deactivate, add, and delete plugins and themes, add new users, add, edit, and remove posts and more. For a comprehensive list of Administrator user capabilities see the WordPress Codex on Roles and Capabilities.


An open-source web server software, most commonly used on Unix/Linux-based machines. Apache is the “A” in a “LAMP stack.”


API stands for Application Performance Interface. APIs exist to help integrate data or tools from a program into your own website. Web developers can integrate APIs from separate companies or services into their own products and innovations.

AJAX (wp-admin/admin-ajax.php)

AJAX stands for Asynchronous JavaScript And XML. Essentially AJAX allows JavaScript to send or receive data via PHP requests in the background. Keep in mind that using AJAX is still taxing to your web server, and should be limited to only necessities.

A Record

A DNS record set with your DNS registrar that points a domain name to an IP address.


An “array” refers to a variable that is able to hold one or more values. The “array()” function is most commonly used for a list of items with an index or association. To read more about PHP arrays, read W3’s developer guide.

Author user role

A WordPress user role associated with users who only need to write and publish content. This user role is able to add, edit, delete, and publish their own posts but is not allowed other administrative capabilities. For a comprehensive list of Author user capabilities see the WordPress Codex on Roles and Capabilities.


Cache is a term used for when a copy of a page or object is stored in an easily accessible layer for faster service. In the example of WordPress, PHP is used to generate each page as it is requested in the web browser. WP Engine’s Page Cache will store a copy of this generated page in cache, so it’s able to be served faster the next time.


In the context of WordPress, a Category is a taxonomy that allows you to group posts which are tagged in the same “Category” structure. Any posts tagged with that category will then show under the slug /category/name. For example if I tagged two posts with “test”, then under /category/test I would see both posts. For more information on Categories and taxonomies in WordPress, check out the Taxonomies Codex.

Child theme

The term “Child theme” refers to a theme that has been “branched” into a version specifically tailored to a site. The child theme inherits the functions and styles of the original theme, but can be modified in whatever ways the specific site needs. For more information, please refer to the WordPress Child Themes Codex page.


CMS stands for Content Management System. WordPress itself is a CMS, offering solutions to create and manage content of many types.


CNAME is a type of DNS record, most commonly set with your DNS Registrar. Whereas an A Record would direct traffic for your domain to a specific IP address, a CNAME directs traffic to another domain. WP Engine highly recommends setting CNAME records with your DNS registrar.

Contributor user role

The Contributor user role in WordPress is designed for team members who contribute to posts but do not publish them or delete the posts of others. For more information on this specific user role, please refer to the WordPress Codex on User Roles.


Cookies are bits of contextual data that sites store in your browser, to gather information about your browsing history. Because we use caching layers at WP Engine, you’ll want to be sure to code with this in mind. Look to our Cookies and PHP Sessions article for more help developing sites with Cookies.


CSS stands for Cascading Style Sheets. These files are used to describe the look and formatting of a document written in a markup language. CSS is designed primarily to enable the separation of document content from document presentation, including elements such as the layout, colors, and fonts. To learn more about CSS, head to W3 for a comprehensive CSS guide.

Custom Post Type

WordPress allows for several different types of Posts (stored in the wp_posts database table), including things like Attachments, Pages, Revisions, and Menu items. Developers can also build on to this functionality by creating other types of Posts. For example, WooCommerce product are also stored in the wp_posts table, as a “product” post type. You can follow WP Beginner’s easy tutorial if you are interested in creating Custom Post Types.


A database is a structured set of data, stored in tables and rows within each table. WordPress uses a Relational Database like MySQL to organize information about your site’s pages, settings, users, and more. To read more about the database structure of WordPress, check out the Database Codex page.


Debug mode is a mode that enables additional WordPress error logging. This mode should be used when troubleshooting issues on your WordPress site, and can be enabled in the wp-config.php file. To read more about Debug mode, see Debugging in WordPress.


DNS stands for Domain Name Servers. This system serves as the “phonebook” of the internet. DNS records tell your web browser at what IP address it can find the website requested.


A site address (for example, something.com) purchased from a Domain Registrar.

Editor user role

A WordPress user role intended for editing posts and pages. This user role can add, edit, publish, and delete posts by any user on the site. This user can also view and edit posts set to “Private.” However, this user role does not have permissions surrounding plugins, themes, or other administrator capabilities.


WordPress allows users to “embed” photos, videos, and frames of other content on sites. Many content sources will automatically embed directly from a link. To read more about Embeds in WordPress, check out the Embeds Codex.

File Permissions

Each of the files within your site’s filesystem has a set of file permissions associated with it. These permissions dictate who can view and access the file. To learn more about File Permissions within WP Engine’s environment, see File Permissions.


The Footer refers to the bottom of the page. This section typically contains copyrights, quick links, credits, and more.

Home page

The Home page of your WordPress site is the main page. In WordPress you can designate a specific Page to be your Home page, or for your Home page to be a running list of your latest posts instead.


A Hook is a type of event. There are two types of Hook: Action Hooks, and Filter Hooks. Actions and Filters are dependent on Hooks to be able to perform the intended event. To learn more about Hooks, check out Action Reference and Filter Reference.

Hosting provider

A hosting provider is a company or organization who provides infrastructure for hosting your website. WP Engine is an example of a hosting provider, as your site’s content resides on WP Engine web servers.


HTML stands for HyperText Markup Language. It is a language used for making webpages. In the WordPress Admin Dashboard you will see a Visual Editor and a Text Editor. The Text editor accepts HTML input to format your page as you’d like.

IP address

IP stands for Internet Protocol. An IP address is a number associated with a device that connects to the internet. This can include computers, routers, web servers, and websites. DNS associates Domain Names with IP addresses, for quick lookup by web browsers.

LAMP stack

LAMP stands for Linux, Apache, MySQL, and PHP. This “stack” of software is a common setup used when setting up a web server. The Operating System is Linux, the web server software is Apache, MySQL is the relational database language, and PHP is the programming language.


Generally the term “localhost” refers to the current machine you are on. Localhost usually refers to an address of, otherwise known as “home.”


Multisite refers to hosting one or more “virtual” subsites within the same WordPress install. This creates a Multisite “network” within the WordPress install. To learn more about Multisite Networks, read Creating a Network.


MySQL is an open-source, relational Database management system. This system uses the SQL query language. WordPress uses MySQL to store data about your posts, pages, settings, users, and more within tables and rows in the Database.


Hosted at your DNS Registrar, your domain’s nameservers serve to translate domain names to IP addresses, and vice versa. The nameservers are what allow you to enter a domain name into the URL bar in your browser instead of an IP address.


A permalink (or permanent link) is the permanent URL for each post and page on your website. You use a permalink to send other people to your content, and it’s also the link other webmasters will use when sharing your work. The URL to each post or page should be permanent and not change, which is where the name comes from. Permalinks depend upon your URL structure, which you can choose in your WordPress settings


PHP is a server-side programming language used in WordPress. Files which are written in PHP will typically end in the .php file extension.


A software extension that provides a specific functionality to a WordPress install. There are over 10,000 WordPress plugins in the WordPress Plugin Repository.


In the context of WordPress, a “redirect” generally refers to URL redirection. You can use redirect rules forward requests to a different destination, when the source or “match” URL is requested. Redirects are commonly used when older content is deprecated, or in site redesign to ensure your site maintains the SEO (Search Engine Optimization) from the older pages. To learn how to set up redirects with WP Engine, check out Setting Up Redirects.


Regex is short for Regular Expressions. Regular Expressions are text strings of “match” code used in rules. The server performs a specific action based on the match strings created using Regex. Most commonly on WP Engine you will be using Regex when creating Redirects. See Common Regex Examples for more information.


Registrars are commercial entities that manages and reserve domain names on the internet. Common examples would be GoDaddy, NameCheap, and Dreamhost.

Responsive design

In WordPress, “responsive” design refers to a plugin or theme that supports both desktop and mobile layouts.

Robots.txt file

The Robots.txt file is a set of rules in a site’s root directory that designates which robots to allow and which are disallowed. This file can also be configured to block specific paths from specific robots, and set rules for how frequently the robots are allowed to hit the site.

RSS feed

RSS stands for “Really Simple Syndication.” In short, RSS feeds are plain-text lists of content sorted from newest to oldest. Other websites and RSS feed readers are able to easily pull information from these feeds to keep users updated.


SEO stands for Search Engine Optimization. In short, SEO is the act of improving a website’s rankings for specific keywords in search engines (Google, Bing, Yahoo, Yandex and Baidu). SEO is a highly important aspect of a website’s success. For a quick guide on SEO Best Practices, check out the Beginner’s Guide from Moz.


FTP stands for File Transfer Protocol. Similarly, SFTP stands for Secure File Transfer Protocol, or FTP with a layer of encryption. SFTP is the method you can use to connect to your site’s filesystem on WP Engine. For information on how to get started with SFTP, please see How to Use SFTP.


Shortcodes are used in WordPress as a way to embed a specific macro or piece of code into your site’s content. For more information on how to use shortcodes, check out Shortcodes in the WordPress Codex.


A “slug” is the URL-friendly version of a post title. Slugs are most often used with the Permalink structure selected for your site, or for custom post types as well.


SSL stands for Secure Socket Layer. It is the industry standard security protocol for encrypting a link between a server and a user’s web browser. SSL serves to protect credit card data, login information, file transfers and many other forms of data exchange on your website. To use SSL on your site you will need an SSL certificate. WP Engine offers many SSL options. To read more, see Adding SSL to Your Site.

Subscriber user role

Subscribers are the lowest-level user in WordPress by default. These users have read-only access to the website, which means they have no administration or editing privileges.


Taxonomy refers to the organization and classification of your content. Each Post or Page can have many attributes likes tags and categories. These are examples of the taxonomies within WordPress. Look to register_taxonomy() in the WordPress Codex for more information on Taxonomies.


A WordPress theme refers to the appearance or ‘skin’ of a WordPress website. A theme is a collection of files that produce the overall look, design and user interface of your website. Users are able to build, purchase, and modify themes.Themes are meant to give Administrators aesthetic control over their websites without altering the underlying software.


Trackbacks or Pingbacks are a way to let another site know you’ve referenced their content. They are a good way to give proper credit to an author for referencing their ideas on your own blog. To read more about how Trackbacks work, see Intro to Blogging: Trackbacks.


TTFB stands for Time to First Byte. This measurement refers to the amount of time it took for the web server to generate the page or resource requested. If your TTFB is high this can indicate that either the PHP code and database queries to generate your page took a long time, or the web server was slow to respond. Read Troubleshooting High TTFB for more information.

Uploads (Attachment)

Uploads are files which users upload through the WordPress Admin Dashboard, either in the Uploads section or when attaching a file to a Post or Page. WordPress stores uploads in the /wp-content/uploads/ path on your web server.


A URI (Uniform Resource Identifier) or URL (Uniform Resource Locator) is an absolute identifier of the path where a specific resource is located. For example: http://mydomain.com/wp-content/uploads/2017/09/mycat.jpg

Web server

A web server is a computer, computer system or or specific software that processes HTTP requests. A web server hosts websites, stores data, processes access requests and distributes content.


In WordPress, a widget refers to a simple box (usually connected to a plugin or theme function) you can add to a sidebar, header, footer or other area of your site. You can add widgets to connect to your Twitter account so it can display your tweets, list your various blog post categories or contain a newsletter signup form. Widgets are user friendly, versatile and easy to use. For more information, check out WordPress Widgets on the WordPress Codex.

WordPress Admin Dashboard (wp-admin)

The WordPress Admin Dashboard is the “backend” of the WordPress CMS. This is where all content creation, editing, and publishing takes place. You can add and edit plugins and themes within the WordPress Admin Dashboard. The URI path for the WordPress Admin Dashboard is yourdomain.com/wp-admin/.

wp-config.php file

You can find your site’s wp-config.php file in the root of your WordPress site. The wp-config.php file contains configuration options, settings, and Database connection details. On WP Engine there are some platform-specific settings in this file which should not be edited.

wp-content folder

The wp-content folder stores each site’s individual content. You can find all your site’s themes, plugins, and uploads within this folder.

One install, numerous sites

With WordPress Multisite, you can build and manage more than one WordPress site per install. Save your time and energy by managing similar sites from the same backend.

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