3.1 Introduction

Before I go on to discuss the history of hypertext and hypermedia, I have to explain these two terms. In contrast to a traditional book which has a linear structure, i.e., it is read sequentially from the beginning to end, hypertext is non-linear. Chunks of text are interlinked with so-called hyperlinks which consists of a source anchor and a destination anchor. The source anchor can be a highlighted word in the text which, when selected, leads the reader to the destination anchor which can be a whole document, a paragraph, or just a single word in another chunk of text. Authors of hypertext have to take care because they cannot presume that the reader has read any text prior to that currently displayed.

Hypermedia is a more general term where the chunks of text found in hypertext are replaced by chunks of any media, like images, audio, video, 3D objects, etc. Again, hyperlinks connect these chunks, called documents or nodes. Also anchors can be of any kind of media, such as a string, a part of an image, a 3D object, or even parts of audio or video clips.

A collection of interlinked documents is called a hyperdocument.