Thank you. And am I right in thinking that the route contains 'shaping points' in a kind of 'take me along this way but not precisely', sort of way and the track is a continuous line which must not be strayed off?
Sort of, yes.
All routes must have two fixed points, A (the start) and B (the end). These can be joined by the algorithm of an app, with no intervention by the rider. In other words, the algorithm chooses the roads in between. The roads in between are marked by many invisible points, ‘visible’ only to the gps device.
You can then have a route, again from A to B, where you (the rider) dictates the roads to be ridden between the two fixed points. You shape the route by inserting shaping points, placed on the roads that you want to pass along. The algorithm then fills in the gaps with invisible marks, which the device can read.
Tracks are (most commonly) recordings of where you have ridden, a trail of breadcrumbs if you like. But, they can also be a version of a route, too. In the latter, the app takes the route, looks at the line from A to B or from A to B, via points 1,2,3,4 and 5 and inserts maybe thousands of invisible points in between, again like a trail of breadcrumbs.
So, why have both? There are various reasons, but I guess the most common are:
Tracks are fixed, they will not alter if you go off route or, more truthfully, ‘off track’.
Tracks will not have any voice prompts in them, like “Turn left in 300 yards”. Some devices have no ability to relay voice instructions, so using a track makes good sense.
Some owners like to have a route displayed, to use its voice prompts and (maybe) allow recalculations, but also have the fixed track displayed at the same time. Not all devices are capable of showing this dual route-and-track display.
Some owners only ride off-road, where there are no roads for a route to follow. They must use a track, by default.
