I have some questions about the WP Super Cache plugin. Should I use it? Is it a good plugin or should I deactivate it? Will my site load faster with this plugin? But does it load faster only when a user visits my website another time, not the first time when (s)he visits it?
Essentially what it does is takes a picture of your website after it loads, and instead of loading PHP and MySQL for that page for every visitor it shows the picture instead. The Wordpress Core still has to load so there will still be a delay in loading, but it can take a 7 second site down to 3 seconds very quickly. There are different styles of caching but the main style is page caching. There is also DB caching and Server Caching. I believe that DB caching stores the data that a certain query returns in memory so the data can be quickly recalled without polling the mysql database again and again. Server caching is more difficult. I don't know too much about it. I'm still new at all this too. When caching we can set the cache to expire so it regenerates a new build every 30minutes to 1000 days... depending on how long the admin would like a cached page to remain cached. Most caching plugins auto-purge a page and the site homepage after that page has been updated, so users are automatically served the latest version of a page, but some caching plugins do not clear the cache for tag and archive pages so those can show old content until the cache rebuilds. I use WP Quick Cache due to it's simplicity... my least favorite plugin is W3 Total Cache due to it's complexity.
It is really good. And no need clean cache. Every time you update your wordpress it will clean the cache by itself. So you don't need to do anything.