Tags on the Internet are labels that the users specify for different web contents, such as blog entries, the contents of so-called social bookmarks, or photographs in picture galleries. When they use tags, the users produce meta-information based on key words; when key words are given for different things, semantic webs are created to make information searches easier.
Flickr is one example of an Internet service that uses tags. Flickr is one of the many picture galleries on the Internet, where users can post their own images. When uploading the pictures, the user specifies tags for each picture. The tags tell us what the picture is about. In the following image, you can see some tags related to the picture of the squirrel:
After you have tagged your pictures, other Internet users will be able to find it easily on the basis of its contents.
Methods that Internet users can employ to distribute their own favourite web pages, i.e. the pages they have bookmarked in their web browsers, are called social bookmarks. There are many services with which users can share their bookmarks. One of the most famous services is del.icio.us. Among other features, this service lets you tag your own bookmarks for distribution e.g. among your friends.
You can use the del.icio.us service with your browser, e.g. Firefox, after installing a browser plug-in called del.icio.us. The images below show how to use del.icio.us with Firefox. When you are on a web page that you want to share with others, click on the Tag button shown in the top image, then fill in the description and tags in the form shown in the bottom image.
When you have stored the bookmark by clicking on Save, your friends will see the link. In order to use this service, you have to ask your friends to create a del.icio.us account and to share bookmarks among themselves. The following image shows the del.icio.us account of user Raymond Keskivarsen, who is logged on to the service, and which bookmarks Raymond has received from his friends.