Introduction

Computers aren't yet very good at understanding and interpreting images. Presented with two images, one of a horse and another of a tree, in the absence of any other information, a computer would not be able to tell you the difference, or very much else useful about them.

And so we have metadata - literally data about data; textual information that tells us everything we need to know about our images and helps us find them. Metadata allow us to say'show me all the pictures of horses, but not the ones with trees in'and to ask other questions that go well beyond the equine and arboreal.

Broadly speaking, metadata fall into one of two camps. Either they're added by the camera at the time the image is shot or they're added afterwards. The first kind are sometimes referred to as Exif metadata are easy to deal with because, for the most part, they're added automatically and you can't edit them, but you can use them as the basis for searching for photos.

The second kind, usually known as IPTC metadata, are added and edited manually, after the event. Consisting, among other things, of caption and credit information, location data and keywords, which describe the image content, they are the stuff that helps to differentiate between foals and foliage.

Aperture provides powerful tools for adding, editing and searching metadata. Using them to organize and identify the content in your image Library will help you locate it when you need it...