Geocache Or a specific location on a map that you want to go to or bike to (using your bike)
but as for tracks or routes they would be uploaded but will not work on the 205.
All geocache is put into memory and it won't be visual if you try to see them when looking
however, you can only pic then under favorites
I would say that the best thing for you to do is to find a used eTrex handheld unit for a good nice price with a bike mount and for sure all your problems will be fixed.
here is an en example of a good started GPS Handheld