Many times in Attack on Titan, the various soldiers mention something called "three-dimensional maneuvering", which appears to be an effective strategy for the battles with the Titans. At the end of chapter 3, there is a "rough explanation" about it:
However, it doesn't really explain what three-dimensional maneuvering is, and the manga doesn't seem to show very well what the soldiers are doing when they perform these maneuvers. Logic would dictate that a three-dimensional maneuver can be any maneuver since movement in the real world is in three dimensions. However, this term seems to mean something specific.
What is a "three-dimensional maneuver", and how is it special or effective against the Titans?