GNSS stands for Global Navigation Satellite System, while GPS stands for Global Positioning System. The primary difference between the two lies in their scope and origin.

GPS specifically refers to the navigation system developed and maintained by the United States. It consists of a constellation of satellites orbiting Earth, broadcasting signals that allow GPS receivers to determine their precise location anywhere on the planet. Originally developed for military purposes, GPS is now widely used for civilian applications such as navigation, mapping, surveying, and timing synchronization.

On the other hand, GNSS is a broader term that encompasses, GNSS systems include:

• BeiDou Navigation Satellite System (BDS), 31 satellites in orbit, developed by China.
• GPS （Global Positioning System), 45 satellites in orbit, developed by United States.
• GLONASS (Global Navigation Satellite System), 24 satellites in orbit, developed by Russia.
• Galileo, 27 satellites in orbit, developed by the European Union.
• NavIC, 5 satellites in orbit (Navigation with Indian Constellation), developed by India.

Each of these GNSS systems operates similarly to GPS, utilizing a constellation of satellites to provide positioning, navigation, and timing services. GNSS receivers are capable of utilizing signals from multiple satellite constellations simultaneously, enhancing accuracy, reliability, and availability of positioning information, especially in challenging environments where signals from one system may be obstructed or degraded.