Motion tracking, or match-moving, is the term used to describe the simulation of live-action camera moves and perspective inside compositing software such as After Effects, Combustion, Shake or Flame for 2D, and Boujou, PF Track, SynthEyes or Matchmover for 3D. It's commonly used to apply special effects to feature films and commercials, but it's becoming more common within type and character animation in motion graphics.
There are several types of motion tracking in both 2D and 3D. In the 2D environment your options range from tracking the X and Y-axis along with zooms and rotation on the Z-axis. You can also use motion tracking to stabilise a shaky or unstable shot. Motion tracking in 3D is for complex camera moves across all three axes. Three-dimensional tracks allow for dimensional objects created in 3D software, such as extruded type or character models. Though 3D tracks definitely have their advantages, they shouldn't be used unless necessary, because they add a new level of complexity and more work.
