POCKETDOOR
Pocket door
A pocket door is a sliding door that disappears, when fully open, into a compartment in the adjacent wall. Pocket doors are used for architectural effect, or when there is no room for the swing of a hinged door. They usually travel on rollers suspended from an overhead track, although some also feature tracks or guides along the floor. Both single- and double-door versions are used, depending on how wide an entry is desired.The above text is a snippet from Wikipedia: Pocket door
and as such is available under the Creative Commons Attribution/Share-Alike License.