A GPS navigation device is any device that receives Global Positioning System (GPS) signals for the purpose of determining the devices current location 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 in military, aviation, marine and consumer product applications.

GPS devices may also have additional capabilities such as, containing maps, which may be displayed in human readable format via text or in a graphical format, providing suggested directions to a human in charge of a vehicle or vessel via text or speech, providing directions directly to an autonomous vehicle such as a robotic probe, providing information on traffic conditions (either via historical or real time data) and suggesting alternative directions and providing information on nearby amenities such as restaurants, fueling stations, etc.

In other words, all GPS devices can answer the question Where am I, and may also be able to answer, which roads or paths are available to me now, which roads or paths should I take in order to get to my desired destination, if some roads are usually busy at this time or are busy right now, what would be a better route to take, where can I get something to eat nearby or where can I get fuel for my vehicle.

Consumer GPS navigation devices include, dedicated GPS navigation devices, GPS modules that need to be connected to a computer to be used, GPS loggers that record trip information for download. Such GPS tracking is useful for trailblazing, mapping by hikers and cyclists, and the production of geocoded photographs, converged devices, including GPS Phones and GPS cameras, in which GPS is a feature rather than the main purpose of the device. Those devices are the majority, and may use assisted GPS or standalone (not network dependent) or both. The vulnerability of consumer GPS to radio frequency interference from planned wireless data services is controversial.

Dedicated devices have various degrees of mobility. Hand held, outdoor, or sport receivers have replaceable batteries that can run them for several hours, making them suitable for hiking, bicycle touring and other activities far from an electric power source. Their screens are small, and some do not show color, in part to save power. Cases are rugged and some are water resistant.

Other receivers, often called mobile are intended primarily for use in a car, but have a small rechargeable internal battery that can power them for an hour or two away from the car. Special purpose devices for use in a car may be permanently installed and depend entirely on the automotive electrical system. The pre-installed embedded software of early receivers did not display maps, 21st century ones commonly show interactive street maps (of certain regions) that may also show points of interest, route information and step by step routing directions, often in spoken form with a feature called text to speech.