meta- implies a state of transcendence. It’s used to describe the derivatives and successors of a lot of different things (think
metaphysics). It should come as no surprise then that metadata is often described as “data about data.” What may be surprising, however, is just how much data about your data is available. While the file’s owner and filename would be obvious picks, there are many other pieces of metadata embedded in your files.
Take a snapshot from your digital camera as an example. In addition to the basic information that can be derived from the filesystem, even more details are kept in the Exchangeable Image File Format (EXIF) data within the file. This information was added to the file by your digital camera when you snapped the picture. These tidbits of data are not only valuable when working within your imaging software, but they are also indexed in the Spotlight data store for searches down the road.
The introduction of Spotlight technology in Mac OS X Tiger has brought file metadata to the foreground. Spotlight is a powerful tool for searching your data, but it’s much more involved than belied by the simple search box presented when you click the Spotlight icon in the menu bar. Spotlight is constantly running in the background, updating its data store whenever the files on your drive change, and making the latest content and metadata available for immediate searching.
At the same time, it is handling search requests ...