6.1 Hypertext Basics

A fundamental feature of hypertext is that you can hyperlink documents; you can point to another place inside the current document, inside another document in the local collection, or inside a document anywhere on the Internet. The documents become an intricately woven web of information. (Get the name analogy now?) The target document usually is somehow related to and enriches the source; the linking element in the source should convey that relationship to the reader.

Hyperlinks can be used for all kinds of effects. They can be used inside tables of contents and lists of topics. With a click of the mouse on their browser screen or a press of a key on their keyboard, readers select and automatically jump to a topic of interest in the same document or to another document located in an entirely different collection somewhere around the world.

Hyperlinks also point readers to more information about a mentioned topic. "For more information, see Kumquats on Parade," for example. Authors use hyperlinks to reduce repetitive information. For instance, we recommend you sign your name to each of your documents. Rather than including full contact information in each document, you can use a hyperlink to connect your name to a single document that contains your address, phone number, and so forth.

A hyperlink, or anchor in standard parlance, is marked by the <a> tag and comes in two flavors. As we describe in detail later, one type of anchor creates a hot spot in the document that, when activated and selected (usually with a mouse) by the user, causes the browser to link. It automatically loads and displays another portion of the same or another document or triggers some Internet service-related action, such as sending email or downloading a special file. The other type of anchor creates a label, a place in a document that can be referenced as a hyperlink.^[1]

^[1] Both types of anchors use the same tag; perhaps that's why they have the same name. We find it's easier if you differentiate them and think of the type that provides the hot spot and address of a hyperlink as the "link" and the type that marks the target portion of a document as the "anchor."

There also are some mouse-related events associated with hyperlinks, which, through JavaScript, let you incorporate some exciting effects.