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 Geneva.JPG
Creation Date2012-03-12 12:35:54
File Size343,674 bytes (335.6 KB)
Dimensions1024 x 768 pixels