Because this course is part of the World Wide Web, any user on any computer system, connected to the Internet network, and using a WWW browser, can read this hyperdocument just like you do. Some links in this course transfer and display information which is located on different sites throughout the world. To the user the whole distributed database of information appears as one hyperdocument. When you click on an anchor, you may not notice whether the link will simply show you another screenful of information from this course or a screenful of information from any other site on the network. When you jump to a document that does not belong to this course text you will most likely not see the "banner" you see on all course pages. Another indication is the Uniform Resource Locator (URL) of the document you are viewing. URLs are normally briefly shown by the browser before you follow a link, and may be permanently displayed while viewing a page. The URL is a unique address for the destination of the link you are about to follow. It shows the name of the site containing the destination, as well as the destination's name. Clicking on an anchor may download a picture, an audio fragment or even a (compressed) video fragment, each of which can be very large. This only works well if you have a fast connection to the Internet.
All documents (nodes) in the World Wide Web are written in the same generic markup language: HTML. However, different versions of the HTML standard exist. This course assumes you are using a browser capable of correctly displaying documents written in HTML-3.2. Many other documents on WWW use features that are not part of this standard, for example frames (introduced by Netscape).
Apart form access to WWW servers and HTML documents, most WWW user-interfaces offer gateways to information written in other languages, or using different communication protocols, such as Gopher.
Some anchors in the current node are linked to information on different sites, as close as Eindhoven, and as far away as Illinois and Massachussets. If you click on either of these you will be leaving this course and take off on a journey through the World Wide Web.