GLONASS
The Russian version of GPS. The two systems are separate, but similar in design and function.
See: GPS
Generically, such systems are called global navigation satellite systems (GNSS).
See: GNSS
There are multiple GNSS in operation for Earth, including Europe's Galileo, China's BeiDou, and India's NavIC. They work similarly to GPS and GLONASS, but each is operated separately.
Phones and other devices can use multiple GNSS simultaneously to improve location accuracy and speed.