Probably application-specific. Satellite for ships, cellular for commercial trucks, radio for remote mining trucks.

There are also panic buttons for remote backpackers that collect gps coordinates and send them to a satellite. All things I wouldn't call satellite phones, even if they're basically just more rudimentary versions. Looks like the quote was referring to something else, though.

They use cell service or sat phone or some kind of sat service like GlobalStar. And they're suggestively called trackers, so there is no expectation of privacy.

GNSS receivers are passive devices just like regular radio receivers, but in addition to regular radios they use math to process the deltas from GNSS satellite clock signals to pinpoint their position.