Absent without leave

The term absent without leave - or AWOL referred to a member of an armed forces who either left their base or assigned station, without permission, or did not return from a vacation, on time.

It is considered much less serious than desertion - as someone who is AWOL is assumed will eventually return to their duty.

If a period of absence without leave extends too long the individual is likely to be reclassified as a deserter.