Table of contents

Appendices

2.1 Links and Resources

An XLink link is an explicit relationship between resources or portions of resources. It is made explicit by an XLink linking element, which is an XLink-conforming XML element that asserts the existence of a link. There are six XLink elements; only two of them are considered linking elements. The others provide various pieces of information that describe the characteristics of a link. (The term "link" as used in this specification refers only to an XLink link, though nothing prevents non-XLink constructs from serving as links.)

The notion of resources is universal to the World Wide Web. As discussed in [rfc2396], a resource is any addressable unit of information or service. Examples include files, images, documents, programs, and query results. The means used for addressing a resource is a URI (Uniform Resource Identifier) reference (described more in [Locator Attribute (]). It is possible to address a portion of a resource. For example, if the whole resource is an XML document, a useful portion of that resource might be a particular element inside the document. Following a link to it might result, for example, in highlighting that element or scrolling to that point in the document.

When a link associates a set of resources, those resources are said to participate in the link. Even though XLink links must appear in XML documents, they are able to associate all kinds of resources, not just XML-encoded ones.

One of the common uses of XLink is to create hyperlinks. A hyperlink is a link that is intended primarily for presentation to a human user. Nothing in XLink's design, however, prevents it from being used with links that are intended solely for consumption by computers.