the linking of related pieces of information by electronic connections in order to allow a user easy access between them. Hypertext is a feature of some computer programs that allow the user of electronic media to select a word from text and receive additional information pertaining to that word, such as a definition or related references within the text. In the article “whale” in an electronic encyclopedia, for example, a hypertext link at the mention of the blue whale enables the reader to access the article on that species merely by “clicking” on the words “blue whale” with a mouse. The hypertext link is usually denoted by highlighting the relevant word or phrase in text with a different font or colour. Hypertext links can also connect text with pictures, sounds, or animated sequences.

Hypertext links between different parts of a document or between different documents create a branching or network structure that can accommodate direct, unmediated jumps to pieces of related information. The treelike structure of hyperlinked information contrasts with the linear structure of a print encyclopaedia or dictionary, for example, whose contents can be physically accessed only by means of a static, linear sequence of entries in alphabetical order. Hypertext links are, in a sense, text cross-references that afford instant access to their target pieces of information. Such links are most effective when used on a large array of information that is organized into many smaller, related pieces and when the user requires only a small portion of information at any one time. Hypertext has been used most successfully by the interactive multimedia computer systems that came into commercial use in the early 1990s.