As already said it gives you a breadcrumb to follow, you can add “track points” for junctions and turns if you save your route as a tcs file. The device will then give you a countdown in time/distance to track point and the action to tack (Left, right, straight on) it also gives you an visual and audio cue when you get to that point.
The 500 also gives you a audio and visual warning when you go off route.
One thing to note, track points can not be added through the Garmin Connect software available online, You can add them easily via bikeroute toaster for road rides, but I’ve not found a good solution for offroad rides…although to be honest I haven’t looked that hard.