metadata

I meant to define "metadata" in my blog post and forgot. Metadata is "data about data." An example of metadata is information attached to a Photoshop file. The Photoshop file is made up of data--in a color image, this would consist of pixels composed of values between 0-255 for red, green and blue (for a total of 16.7 million possible colors). The metadata attached to the file indicates what kind of camera shot the image, what the f-stop (aperture) and exposure length (shutter speed) were, focal length of the lens, whether the flash fired, document file format, file size, date created/modified, and keywords added to assist in searching. (This list is not complete, and is an example for just one kind of file.)