Layers as Groups

[cekuhnen]

true if you want to - but layers are much more about visibility or locking a layer and all the objects inside.

You can if you want make a group called a layer then yes it is the same.
But you can also make a group just collect objects.

What they can be or not is one thing, how you can use the terms to describe two different function is much more interesting.

[el_diablo]

Blender layers are not layers semantically, they are more like sequentially named groups already. Yes the interface separates them for the user, but they are essentially the same in function with groups being a superset.