In the year 2000, the US Government enabled their Global Positioning System (GPS) of satellites to provide location accuracy up to 6-20 feet.  For the first time  individuals could accurately record the location of an object via GPS technology so that another might find it easily.  This event launched the sport of Geocaching.

Throughout the world "caches" (pronounced cash-es - as in money) are hidden in publicly accessible locations.  These caches take the form of ammunition (ammo) boxes, plastic containers, and 35mm film canisters.  Their locations are defined by longitude and latitude (co-ordinates) readings and then recorded on the website

An electronics device called a GPS unit (or receiver) is used to help you find these hidden caches.  You enter the coordiantes into the unit and it will show you on an electronic map how far away from the cache you are and in which direction.  Given a GPS unit will only get you to within 6-20 feet of the cache, additional hints may be given on locating the hidden spot.