Sliding door
Short definitionA door with a leaf that slides along the wall. Used for wide openings with forklift traffic. It needs clear wall beside it to slide into.
Because the leaf does not swing forward, it takes no space in front of the door. It suits wide and tall openings. In return, it needs clear wall on one side of the opening, at least as wide as the leaf.
This sliding clearance is the thing most often forgotten in design: there must be no other door, column or corner where the leaf will slide. It can be manual or motorised.