What is a WordPress Plugin

A WordPress plugin is a set of files containing various programming languages that can be added through a simple installation process to websites operating on the content management system known as WordPress. WordPress plugins are built to create additional functionality for web developers by creating a graphical user interface. This allows non-programming web developers and bloggers the ability to customize their websites without needing programming knowledge.

In order for a WordPress plugin to be recognized as a WordPress plugin, it requires what is called a plugin header. Plugin headers are located in the primary PHP file of a plugin and include various pertinent facts about the plugin. Information found in the plugin header may include items such as the name of the plugin, the plugin author, a plugin version number, etc. The main PHP file that contains the plugin header will be added to a folder traditionally titled by the name of the plugin and then compressed into a zip file.

WordPress plugins are predominantly written by WordPress developers in a programming language called PHP. WordPress developers use the WordPress Codex to research various shortcuts called actions & filters and to learn how to implement a clear set of guidelines and recommendations put forth by WordPress. The content management system itself is built to use PHP, however popular languages such as jQuery and JavaScript are also used in plugins, as are cascading stylesheets, or what is also referred to as CSS. These files are organized into structured directories, which are then added to the main directory.

When a WordPress plugin is ready for production, it is either uploaded to the WordPress repository, listed on an ecommerce platform such as CodeCanyon or sold directly. While WordPress is an open-source platform, WordPress plugin developers who sell plugins are technically charging for their support. Since plugins interact with WordPress through PHP, a server side language, it is common for users of a particular plugin to request custom snippet support to modify the behavior of the plugin or require additional customization and features.

Virtually all plugins create a new settings page, in which the settings allow customization of the features offered by the plugin. For example, if the plugin is a form builder plugin that allows the web developer to build forms, then the settings page may have form inputs that are used to determine the form title, input labels, input types, and the input descriptions. The plugin settings are then saved to the database and implemented when a user or customer is viewing the form. The plugin settings are the graphical interface used to allow a non web developer to make changes to their website. A graphical interface is a user-friendly design that eliminates the coding aspect of web development.

WordPress plugins use what are called actions and filters to implement the plugin's settings. Actions and filters are built-in functions designed by WordPress that trigger specific functions at specific times. A function triggered by an action or hook may contain a database query that retrieves the plugin's settings. Once the plugin settings have been retrieved, the settings can then be implemented. For example, when a specific form is being viewed, the plugin settings could be used to determine the various input fields to add, conditional logic to apply, if the input if required, etc. WordPress plugins depend on actions and hooks to implement the plugin's features and are required in order to be functional.

A WordPress plugin offers a variety of benefits to the WordPress administrator, allowing them to make changes to their website, enhance their website's functionality, increase site performance, edit design aspects or customize a specific flow to better suit their needs. With over 60,000 WordPress plugins to choose from in the WordPress repository, WordPress plugins are an essential aspect of building websites with WordPress.