A GPS receiver is a device that determines its location using signals from Global Positioning System satellites. It calculates the receiver's position by measuring the time it takes for signals to travel from multiple satellites to the receiver. This information allows the device to provide accurate location data, typically in terms of latitude and longitude. GPS receivers are commonly found in various devices, including smartphones, car navigation systems, and handheld GPS units. They are used for a wide range of applications, such as navigation, mapping, and tracking, making them essential tools for travelers and outdoor enthusiasts.