gnome-disks write caching

in **RHEL/CentOS 7.9** anyway, when running gnome-disks which is under the Applications-Utilities-Disks menu, for a recognized SSD it offers the enabling of **write-cache**. I would like to know what technically is happening when turning this on, that wasn't already happening. *I was under the impression, whether it was an SSD or a conventional spinning hard disk, that linux inherently does **disk caching**. This impression mainly comes from reading that www.linuxatemyram.com page years ago.*