As such, your site should not require any other maintenance than updating the content regularly.

However, if you use the caching feature in modules, it can result in a performance gain to clear the cache once in a while, to get rid of un-used cached files, so it is faster for the system to retrieve an often-visited page.

This clearing is done by going to the System Admin module in the administration, then to Preferences and then to General Settings. Even if there are no changes in the form, submitting it will clear all cached files.

Modules with preferences will also clear all cached files for that module only, by submitting the preferences form.