A GPS navigation device is a device that receives Global Positioning System (GPS) signals to determine the device's location anywhere on Earth. GPS devices provide latitude and longitude information, and some may also calculate altitude, although this is not considered sufficiently accurate or continuously available enough (due to the possibility of signal blockage and other factors) to rely on exclusively to pilot aircraft. GPS devices are used by the military, by aircraft pilots, by sailors/boats, in vehicles for tracking position and for recreational purposes by the public.
GPS devices may have capabilities such as:
maps, including streets maps, displayed in human readable format via text or in a graphical format,
turn-by-turn navigation directions to a human in charge of a vehicle or vessel via text or speech,
directions fed directly to an autonomous vehicle such as a robotic probe,
traffic congestion maps (depicting either historical or real time data) and suggested alternative directions,
information on nearby amenities such as restaurants, fueling stations, and tourist attractions.
GPS may be able to answer:
roads or paths available,
roads or paths that might be taken to get to the destination,
if some roads are busy (now or historically) the best route to take,
The location of food, fuel or other needs,
the shortest route between the two locations.