The cool thing about UNIX is that all of the command information is right at your finger tips First step is to use the man pages. Try typing man mount at the command line. To understand mount, also read about file types and mount points.

Mount
All files accessible in a Unix system are arranged in one
big tree, the file hierarchy, rooted at /. These files
can be spread out over several devices. The mount command
serves to attach the file system found on some device to
the big file tree. Conversely, the umount(8) command will
detach it again.
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