A pocket door is a door that slides into an opening in a wall.  The doors slides straight into the wall, and does not swing from either side, as in a hinged door, which swings from one side of the door jamb. Here is an illustration of how this door slides into the wall for both single doors and double doors.

     Single Pocket Door Illustration
Double Pocket Door Illustration
Instead of hinges, the door is held in place by an overhead track, rollers, and door guides towards the bottom of the pocket door jamb.  The doors slide completely into the wall and out of the way. You can save up to 15 square feet of usable space per pocket door in your home. You can purchase complete pocket frame kits, or loose track and hardware to make your pocket in your wall. For closing, or locking, there is a variety of hardware available, including passsage locks, which only fasten to the jamb, and not lock.  The next type is a privacy lock, which has a lock that just turns from one side to lock a door in place.  The most secure type of lock for pocket doors locks with a key.
See all the available custom interior doors for your next pocket door job at InteriorDoors.com . For all the hardware discussed here, see PocketDoorProducts.com