In terms of a GPS, a Route is an intended way to go from A to B, along a particular route. It will give you the shortest distance between the two, but if you want to follow particular roads, you will have to set a series of waypoints to achieve this.
A Track is a bread crumb trail of where you have been, while the GPS is on. Tracks can be used in OziExplorer to highlight tracks on a map then uploaded to the GPS. It is simply a matter of following the track on the GPS which will follow the track turn by turn, depending on how accurate your map is.
I hope this helps!