A hyperlink has an anchor, which is a location within a document from which the hyperlink can be followed; that document is known as its source document. The target of a hyperlink is the document, or location within a document, that the hyperlink leads to. The user can follow the link when its anchor is shown by activating it in some way (often, by touching it or clicking on it with a pointing device). Following has the effect of displaying its target, often with its context.
In some hypertext, hyperlinks can be bidirectional: they can be followed in two directions, so both points act as anchors and as targets. More complex arrangements exist, such as many-to-many links.
The most common example of hypertext today is the World Wide Web: webpages contain hyperlinks to webpages. For example, in an online reference work such as Wikipedia, many words and terms in the text are hyperlinked to definitions of those terms. Hyperlinks are often used to implement reference mechanisms that predate the computer, such as tables of contents, footnotes, bibliographies, indexes and glossaries.
Web reference: http://en.wikipedia.org/wiki/Hyperlink
