how it works?

Hi Guys, i want to use a GPS Arduino but i need know from where receives positioning information, if the use is priced, if I can have communication Towards gps also and send data or only i can receive from gps and if I can view the trajectory in real time from web? Thankyou So much

You can only receive from GPS. The signal comes from satellites in orbit. To get accurate position the GPS needs to see several satellites. There is no cost to receive the signal. As far as trajectory goes, it depends on the speed. If you need data every second or so then yes you can map your route. If you need data much more often then probably not.