Is a 5-foot step in Pathfinder essentially the same as a Shift movement in D&D 4th edition? I believe that neither movements provoke an attack of opportunity so they sound like the same thing with a different name.
You can move 5 feet in any round when you don't perform any other kind of movement. Taking this 5-foot step never provokes an attack of opportunity. You can't take more than one 5-foot step in a round, and you can't take a 5-foot step in the same round that you move any distance.