A hypertext document is a collection of text documents which reference each other via links, which appear on the screen as highlighted or underlined words. A link is "sensitive": you can click the mouse pointer on it and the document that it references will be displayed.
One difference which sets hypertext apart from ordinary text is that pages can be very short or very long, since there is no paper to worry about. A long page can only be partially displayed in your window. To see the rest, you need to use the scrollbar along the right hand edge of the window.
In addition, this browser window should be showing navigation buttons at the top! If not, make sure you are using Netscape and that the window is showing separate frames. If not, then you may have to return to the top level page by clicking the home icon on the browser (i.e. not the one in the page).
Hypertext is organized (or disorganized) as a "web" of interconnected documents, each one containing links to any of the others. For example, the table of contents above consists of links to the various topics displayed there; think of those pages as lying below this one in an inverted "tree". You can read about those topics just by clicking on them.
Most documents will be structured as a local hierarchy, as this one is. However, they can also contain links to external documents which adhere to different conventions. The structure of this document is explained in section 1.2, How this document is structured .
A program which presents hypertext documents and follows up on any links you may activate is called a hypertext browser. If you are in the Undergraduate Lab you are most likely using a browser called Netscape, or NCSA Mosaic. Both of these browsers are capable of displaying pictures as well as text.
If you get lost out there on the Internet, and you need to get back to this documentation, use the Home button on your browser window.