GPS, or Global Positioning System, is a navigation system that enables a GPS receiver to locate its position anywhere on Earth. It works by receiving signals from at least four satellites orbiting the Earth. These satellites constantly transmit signals with their location and the exact time the signal was sent. The receiver then calculates the distance to each satellite based on the time it took for the signals to reach the receiver. By triangulating the signals from multiple satellites, the GPS receiver can pinpoint its exact location. To ensure accurate positioning, at least four satellites are required as each signal provides a specific coordinate. The reason satellites are necessary for GPS is due to their ability to cover large areas of the Earth's surface. This global network of satellites allows GPS receivers to obtain signals no matter where they are on Earth. Additionally, the satellites are constantly moving, ensuring that the entire planet is covered and that receivers can accurately determine their position in real-time. Without satellites, GPS would not be possible and we would not be able to enjoy the convenience of precise navigation and location services that we rely on in our daily lives.