Hyperlinks are the heart of HTML. They allow the linking together
of remote documents with the convenience of a click or other activation
mechanism. Hyperlinks are used to establish a relationship between two documents:
a source (usually the current document) and the destination. The
destination of a hyperlink jump can be either an entire document or a
specific location within a document. In addition, the hyperlinking element (A)
can play the role of destination for a URL (using the NAME
attribute), the activation point to another URL (using the
HREF attribute), or both at the same time.
The A element has other attributes as well (such as TARGET)
which serve to further communicate information about the source and destination
documents.
Absolute Vs. Relative URLs
A hyperlink destination is defined as a Uniform Resource Locator
(URL) using this general format:
[protocol]://[network
location ID]/[path on
machine]/[file
name]#[internal document location]
This is only a general format for specifying a URL - There are many
variations within this framework (such as a "mailto" URL), and
portions of the format can be omitted (such as the
[internal document location].) Please see
RFC1738 for more
details on URLs.
The path to a document can ALSO be specified relative to the
originating document. In such cases, the
[protocol] and [network
location ID] portions of the above syntax are omitted and
[path on machine] is given relative to the
current file or to a complete URL referenced in the BASE element.