How does a gps system work exactly?

Question

in full detail. Do you download a map from online, or can you only use pre-installed maps. If you can download them can you download foreign maps in other countries? how many kb does it usually use for a length of 10 minutes, and does it recognize where you are by tower communication or do you set where you are and your path first?

Answer 1

Yes, you can upload new maps
Yes, you can download foreign maps
I am not sure what you mean by 10 minutes. Map size depends on area.
It recognizes where you are using a set of navigation satellites. It finds where you are automatically.