Definition - What does Geotagging mean?
Geotagging is the process of adding geographical information to various media in the form of metadata. The data usually consists of coordinates like latitude and longitude, but may even include bearing, altitude, distance and place names. Geotagging is most commonly used for photographs and can help people get a lot of specific information about where the picture was taken or the exact location of a friend who logged on to a service.
Techopedia explains Geotagging
Geotagging location services can be used to find location-specific websites, news and other information. It is based on positions and coordinates and is often directly taken from a global positioning system (GPS).
Some social networking sites and services give out the location of their users, which allows users to know exactly where their friends are as they are logged on to that website (or check-in to the service).
When tagging photos, the tagging may be done by the camera after processing the shot, or it can be applied when the photo is posted online. Some high-end cell phones have built-in GPS, so they can geotag any photos taken using the phone's camera.