/joh'liks/ n.,adj. 386BSD
PORTING UNIX TO THE 386: A PRACTICAL APPROACH
William & Lynne Jolitz
A basic set of utilities is present on the root, both of general user operation as well as necessary supervisory utilities for system recovery and operation.
Utilities: /bin and /sbin
The basic utilities needed for operation of UNIX are found in the two directories: /bin and /sbin. /sbin contains supervisory commands not generally useful to ordinary users, but important for system operation and system management. /bin contains basic commands useful to all UNIX users -- kind of a core group. Both of these directories are kept short and small to minimize the size of the root and the time it takes to search for a command. All other commands (hundreds, usually) are found in the additional filesystems that become active when UNIX is brought up multiuser. To this end, it is important to note that /sbin/mount and /sbin/umount are used to mount and unmount those additional filesystems.