Routes are pre-defined paths created from a group of location points entered into the GPS receiver in the sequence you desire to navigate them.
Location points can be user generated waypoints or points of interest that have been loaded from a map or from a Garmin program
Routes are created on the computer and/or on the device
Tracks act like breadcrumb trails, allowing you to see where you or another individual traveled in the past. This allows you to navigate a path previously taken.