swap

operating system To move a program from fast-access memory

to a slow-access memory ("swap out"), or vice versa ("swap

in"). The term often refers specifically to the use of a

hard disk (or a swap file) as virtual memory or "swap

space".

When a program is to be executed, possibly as determined by a

scheduler, it is swapped into core for processing; when it

can no longer continue executing for some reason, or the

scheduler decides its time slice has expired, it is swapped

out again.

This contrasts with "paging" systems in which only parts of a

program's memory is transfered.

[Jargon File]

(1996-11-22)