how to Mount volumes, drives, and file systems in Raspberry Pi

What does mount mean?
Mount refers to the mounting or embedding of a data medium in the local file system under Linux. It does not matter what form the disk has. This can be a hard disk, a USB stick or a directory share of a NAS with NFS or Samba in the local network.
It should be noted that under Linux no hard disks or USB sticks are mounted, but file systems.