The word "tag" has many different meanings (32 on dictionary.com), but a new meaning and use for the word has arisen in modern life; tagging on the world wide web. The traditional way of ordering information was through strict categorisation, or taxonomy. This is, for example, how information used to be stored in archives, how it is stored in libraries etc. It is very slow to navigate, and often needs experts to actually find anything. However, a new method of ordering data, called folksonomy (a term coined by the information expert Thomas Vander Wal) has emerged from the internet, and tagging is at the forefront of this information revolution.

Tagging is where information - this might be videos on youtube, bookmarks on del.i.cious, articles on Wikipedia etc. - is given an identifiable "tag". This means that search engines which have the capability of finding these "tags", can do so. This is the secret behind the awesome power of Google and other search engines. This is why you can find information so quickly on the internet. It was not something that was created by information experts, but by people like you and me, who put information on the web. It is a democratic, free process.