Could someone tell me the difference please!
A track is a set of samples taken from your positions on a trip. They can be taken at specified spacings (50'...) or specified times (10 seconds....) or "automatic" which applies travel speed and distance to set a sample rate. Generally there are lots of sample points in a track. A tracklog will reflect the path you have traveled. You can "trackback" a track log to run your trip in reverse or replicate it again later in your original direction.
A route usually contains a few points in sequence. These are used by your computer or GPSr to calculate the route that will pass through the points you want to go to. A route has a start, end, and "via" points. If your GPSr or computer are set to "follow road", and you have a routable map, then the route should follow roads or trails to pass through all the points in the route. If it is not set to "follow road" the route will be a set of straight lines connecting the points.
On the same note:
what happens if you are following a route you put into your 60csx, and you divert on another trail for a short period and turn around and come back? A lot of times when i am on the dirtbike, I want to follow a route, but sometimes see a neat trail i want to go check out. I may go up that trail a little ways, but I always come back to my main route. I just don't want to take the chance of messing up the guidance in my city nav and have it re route me some funny way.
You use City Nav on trails? Didn't know it had any. If you are navigating on a fully routable map and you deviate from the original route, the GPSr will "recalculate" (with spoken directions read "nag") the best route between your current location and your destination. I haven't tried to use routes on a non-routable map, but I suspect that if your route is a set of straight lines connecting points the GPSr will re-route you to the nearest point on the route.
Without a routable map, actually the unit will use its basemap, if routable. All the nuvi's have a worldwide routable basemap for example. So you will get routes that aren't optimal, using the roads on the basemap, starting and ending on the nearest road.
I believe my 60csx had some sort of routable basemap, something like "Americas recreational basemap".
Can you say "recalculating". On a Nuvi that is all that happens when you deviate from the route. Unless your next objective is a waypoint and that you missed. Then it will want to reroute you back to the missed waypoint.