Glossary · Websites and content systems
Website plugin
An add-on that extends a website platform or content-management system with additional behavior.
Also called: website plugins, CMS plugin, CMS plugins
Definition
A website plugin adds features to an existing platform, such as forms, search controls, commerce, caching, or editing tools. Its code, configuration, data, updates, and compatibility become dependencies of the site.
Why it matters
Plugin inventory and maintenance affect security, performance, migrations, licensing, and whether important behavior survives a platform change.
Common misunderstanding
A plugin is not automatically portable, maintained, secure, or included in a site backup merely because it appears in the administrator interface.
Related terms
Related system family: Websites & Publishing
Sources
- How the web works (opens in a new tab) · MDN Web Docs
- About repositories (opens in a new tab) · GitHub Docs
Last reviewed July 16, 2026