Nowadays every photo taken with a mobile phone or digital camera contains metadata. This metadata, called Exif data, contains information about your camera, like brand and model name, the dimensions of the image and - when available - also GPS coordinates which reveal the location where the picture was taken.
File NameExample Paris CDG.JPG
Creation Date2012-07-08 10:15:39
File Size219,750 bytes (214.6 KB)
Dimensions1024 x 768 pixels
GPS Coordinates 49.002, 2.57667