Exchangeable image file format (Exif) is a specification for the image file format used by digital cameras. The specification uses the existing JPEG, TIFF Rev. 6.0, and RIFF WAV file formats, with the addition of specific metadata tags. It is not supported in JPEG 2000, PNG, or GIF.
What i like is, it has standard tags for location information by using geocoding apps.
There is lots of EXIF reader/viewer application for Windows, Mac OSX or GNU/Linux available. But i like to read it online sometimes when i’m not on my personal workstation. Try Jeffrey’s Exif Viewer