In the viewports, footsteps represent support periods in space for the biped feet. Moving or rotating footsteps in space is done in the viewports. In Track View, each footstep appears as a block that represents a support period in time for each of the biped's feet. Moving footsteps in time is done in Track View. The footstep position and orientation in the viewport controls where the biped will step.
There are three ways to create footsteps for the biped. The first way is to place footsteps individually, one at a time. The second way is to invoke Biped's multiple footstep creation tools to create a walk, run, or jump animation. The third way is to extract footsteps from raw motion capture data.
A key advantage of the footstep method is the natural adaptation of the biped that occurs when the footsteps are edited in time and space. Editing footsteps in the viewports will allow you to reposition all of the footsteps to move the entire animation.