Most people say GPS the way they say hoover or biro: a brand name that quietly swallowed a whole category. GPS is in fact one specific system, built and run by the United States. The broader family is called GNSS, for Global Navigation Satellite Systems, and your phone happily eavesdrops on several members at the same time.
The United States has GPS. Russia flies GLONASS. Europe operates Galileo, a civilian-first system prized for its precision. China runs BeiDou, now the largest constellation of the lot. India and Japan add regional systems that sharpen coverage over their own skies. Each is an independent flock of satellites singing the same basic song: here is my identity, here is my time.
Why the redundancy? More satellites in view means a faster, steadier fix, especially in cities where buildings slice the sky into narrow strips. A phone that can hear GPS and Galileo and BeiDou at once has more chances to catch four clean signals and shrug off the reflections bouncing off glass towers. If you want the accuracy details, our piece on how accurate satellite location really is gets into the numbers.
None of these systems tracks you back. That bears repeating, because the names sound like agencies out of a thriller. GLONASS is not watching. Galileo is not keeping a list. They are lighthouses, not cameras. The receiving and the reckoning all happen inside your device, and a lighthouse never knows which ships used its beam.
So when a website flashes logos of every constellation and claims it is triangulating a target through the combined network, enjoy the drama, then remember the plumbing. There is no combined network reaching down for a phone number. Our tracking explainer lays out what these constellations can and cannot do, and the answer is more reassuring than the graphics suggest.