<P> (Also called suspended and waiting .) In systems that support virtual memory, a process may be swapped out, that is, removed from main memory and placed on external storage by the scheduler . From here the process may be swapped back into the waiting state . </P> <P> (Also called suspended and blocked .) Processes that are blocked may also be swapped out . In this event the process is both swapped out and blocked, and may be swapped back in again under the same circumstances as a swapped out and waiting process (although in this case, the process will move to the blocked state, and may still be waiting for a resource to become available). </P>

When does a process change state from run to ready