The present article endeavours to demonstrate the working of the GPS, satellite reception, (GPS are the letters of Global Positioning System). Is a method of orientation based on the signals from a series of satellites of the Department of Defence of the United States. The GPS allows access, at whatever moment and from any point on Earth, simultaneous information from between 6 and 11 satellites. As well as giving the position GPS works like a computer that processes and transmits all the necessary information to follow a route: directions or azimuths, differences in level, pace of march, arrival time, creation of routes based on different parts, altitude and direction, etc. Once the information of the route has been down-loaded from the computer, it can be re-arranged. Depending on the programme the icons, colours, names, lines, climbs, etc. can be changed. The use that each one can put to his GPS is, evidently, a question strictly personal (mountain climbing, excursions, skiing, off the track snow boarding, crossing, hunting, fishing, mushroom hunting) so the article is complemented with a comparison between the two GPS most used.<\/p>\n