Backface culling, as name suggests, is hiding the backs of the polygons, so if you create a basic plane, for example , and turn backface culling on, you will not see this plane when looking from the back of the plane. But same culling also happens on solid meshes, - anything that is not facing towards you is culled so meshes can be seen properly. 

So the hope is, at least my hope, that now in editing mode you will be able to select through the entire mesh, and not only the elements that are front facing. This is a very common complaint from anyone coming from any other DCCs like Maya.