What does the filesystem caching do?

[exzachlyvv]

From the documentation https://laravel.com/docs/8.x/filesystem#caching

To enable caching for a given disk, you may add a cache directive to the disk's configuration options. The cache option should be an array of caching options containing the disk name, the expire time in seconds, and the cache prefix:

However, I'm still confused. Does this mean that the disk connection is cached between requests? Or are the files themselves somehow cached? What does "caching for a given disk" really mean?

I think the docs could use a little clarification :D