Like Windows, but unlike OS-X and Linux, the Amiga has a multi-rooted filesystem. That is, you don't have a single “/” root directory that all other filesystems are found under.

On the Amiga, all of the above have alphanumeric names. When you see them used, they usually end with a “:”.

Devices includes things like SER: (serial port), CON: (console/shell) or DF0: (first floppy disk), DH0: (first hard disk). The equivalent on Linux are the files under /dev/. They are not part of the filesystem like in Linux, but they are important to be aware of, especially since their names makes them look the same as volumes and assigns.

Volumes are actual filesystems mounted with a name. E.g. commonly System:, Work: etc., that refer to a filesystem on a partition on one of the disk devices.

Assigns are best described as temporary aliases. E.g. LIBS: (equivalent to /lib, /usr/lib etc. on Linux), DEVS: (equivalent to device driver modules under /lib/modules/ on Linux). You can create your own assigns.