Performance plugins in WordPress help speed up your website by caching pages and optimizing content. First, you install the plugin files, then activate it in the admin panel. After activation, you configure settings to control how the plugin works. When a user visits your site, the plugin caches the page output to serve it faster next time. The cache expires after some time or when cleared, so the plugin regenerates fresh content. If you deactivate or uninstall the plugin, the optimizations stop and your site returns to normal speed. This flow ensures your site loads faster and gives visitors a better experience.