Gallery wrap is the technique of tightly stretching a printed canvas so that the canvas wraps around the sides of the stretcher bars and is affixed to the back of the wooden frame firmly so that there is no noticeable fasteners.
Artwork on a gallery-wrapped canvas
Gallery wrapped canvases stretched over gallery wrap bars usually have additional painted or printed surface covering the outside part of the canvas. You do not see the unpainted or unprinted part of the canvas and it can hang on the wall just like it is. Framing is not required with gallery wrap.
Gallery Wrapped vs. Non-Gallery Wrap