EXIF stands for “Exchangeable Image File Format,” and it is the standard for storing interchangable information in image files. Almost all modern digital cameras record information when an image when it is taken.  EXIF data contains your camera’s make, model, resolution of the image, date and time, exposure, focal length, f-stop, ISO, etc.  EXIF can even tell you what photo editing software was used.  A very few modern cameras have built-in GPS receivers, and also store this information.

For a file in Microsoft Windows, you can view the EXIF data by right clicking on the image, clicking “properties,” clicking “summary” and then clicking “advanced.” The window that pops up is displayed on the right.

This data can be very useful in determining exactly what went wrong or right with a particular photo.  In the old days, you used to have to write down the basic parameters after every shot, wait days for the film to be developed, and then finally learn from what you did.  No more. 

On the popular photo sharing website Flickr, users can view EXIF data, although account holders can choose to hide this information. It is sometimes interesting to see exactly what settings a photographer used to capture a particular image.