A
linux kernel process (
thread, really) that periodically handles the swapping out of unused
memory pages to your
hard disk. It is sometimes called upon to
swap data out on demand when a running process needs more memory and there are no other ways to get it.
Swapping is distinctly different than paging. Swapping involves stopping a process, and copying the entire contents of it's address space (including code) to disk. Paging (moving infrequently touched memory pages to disk) is always tried first if RAM is short.