A plugin is a software add-on that extends or enhances the functionality of a content management system (CMS) like WordPress without requiring custom coding. Plugins allow users to easily add new features, such as e-commerce capabilities, contact forms, or security enhancements, to their websites. Examples of popular plugins include those for search engine optimization (SEO), which help improve visibility on search engines, and image optimization plugins, which improve loading times and performance. Plugins streamline the development process, allowing even non-technical users to customize and expand their site’s functionality.