A waypoint specifies a point that the requested route needs to traverse. Both
destination are themselves waypoints, but a request may specify many more intermediate waypoints with
via as well. See Route Via Intermediate Waypoint for examples.
Waypoints may represent stopover points (that is, points where some time will be spent before retaking the route), or passthrough points that only influence the route's shape, but where no actual stop is carried out.
In addition to a WGS84 coordinate, a waypoint incorporates several other options and details, related to either the physical location point or to the stop itself.
Some examples of options include the stopover time (as described above), and navigational hints such as requiring the route to arrive on a specified duration, or to ignore maneuvers (e.g., turns) at the start of the route for a specified distance.