The Garmin Nuvi is a GPS unit designed for automotive use, guiding drivers to their chosen destinations using turn-by-turn voice directions. Along with the pre-loaded city and street maps, Garmin gives you the ability to download supplemental mapping, such as yearly map updates or different continent data. Depending on your Nuvi model, the device may have limited internal memory. If you want to clear space for other items, you have the option to delete supplemental maps using your computer.