Using Directories in UNIX
You will encounter some standard directory names on most UNIX systems. You already know that all UNIX systems will have a root directory (/). The following sections look at some other common directories.
Standard UNIX Directory Names
The /tmp and /usr/tmp directories are used by the system to store temporary files. Users may also store temporary files there. but beware: The system may purge (or delete) older files from tmp directories periodically, without any warning.
The /dev directory in root contains the special device node files that access hardware on the system, such as tape drives and floppy disks. These device node files can exist anywhere, but by convention they are put into /dev or its subdirectories to ...