To place a computer, usually a laptop computer, into a low-power mode. This involves spinning down the hard disks, stopping network connections, and sending the appropriate signal to all user programs. Also called Sleep mode or Standby. The advantage is that the computer can be "awakened" without having to go through an entire boot sequence, although many programs and operating systems have difficulty in certain situations. Unlike Hibernate mode, the system is still powered on, and as such still consumes battery power.
Also used when relating to programs: when a program is suspended, it will not process information or redraw the screen until it is signaled to continue using SIGCONT. In most Unix-like shells, Control-Z (^Z) will suspend the current foreground process.