SATNAV - Satellite Navigation System is primarily used in cars and uses a GPS to determine the users position on a map. Normally working off a database, either on cd or on a flash card within a portable satnav devide, the user can program it to give directions both visually and audibly to any address within the satnav database.
'Points Of Interest' can also be included in the database allowing the user to choose a location, e.g. shopping precinct, petrol station, amusement park, etc, as well as pinpointing speed camera locations on the satnav map.
Some vehicle manufacturers fit satnav systems within the vehicle on manufacture, though small handheld sat nav's are extremely popular, with most now able to work on battery power and are ideal for use on bikes or even walking the street.