General Info about Caching
Why do we need caching in any of the WordPress environments?
1. WordPress is a Content Management system and the power of it is the ecosystem around it, but when you are using big number of plugins then WordPress will generate different Server and Database requests which on the big number of visitors will slow down the server a lot, because of that having a caching plugin as WP Rocket will help to generate Cache files and instead of doing DB and Server Requests we will show only the cached files.
2. wp-rocket is helping the browser to keep the assets in the browser cache so instead of loading every time from the server it will load from the browser.
3. Priority of loading files - WProcket is helping by prioritizing the assets which have to be loaded.
You can read more about caching and WordPress on the following URL https://kinsta.com/blog/wordpress-caching-plugins/
Why WP-rocket and not other WP Caching plugins?
Most WordPress sites confirm that WP-rocket is one of the best caching WordPress plugins