GPS units, or Global Positioning System units, are devices that use satellite signals to determine a person's exact location on Earth. They are commonly used in cars, smartphones, and handheld devices for navigation and mapping. By receiving signals from multiple satellites, GPS units can calculate latitude, longitude, and altitude, providing accurate positioning information. These devices often come with features like turn-by-turn directions, points of interest, and real-time traffic updates. Many GPS units also allow users to save favorite locations and create routes for travel. They have become essential tools for travelers, hikers, and anyone needing reliable navigation assistance.