Well a PGWP is an open work permit issued after attending a full time course on a study permit for a minimum of 8 months. A PGWP can be issued for 8 months to 36 months depending on length of the course. A plain open work permit is issued in conjunction for example with a spouse study permit or spouse PGWP or an inland spouse PR application among others. An open work permit allows a person to work for any employer and has a specific end date.