There are three basic ways of handling links in DITA, whether they are external hypertext links or links to other DITA files in your docset.

The three kinds of links are:

• Inline links. These are called "Xrefs."
• Topic-generated links. These are called "Related Links." They appear in a block style at the bottom of a page.
• Map-generated links. These are called "Relationship Tables." They also appear in a block style at the bottom of a page. But they are not hard-wired in the Topic.

In general, links that are internal to the Topic (both Xref and Related Links) are discouraged because they require the linked-to resource to be present at runtime.

Links generated by Relationship Tables, called "reltables" by the ditascenti, are the most flexible. They can vary from map to map.

Reltables are called tables because the user interface for creating them comes in the form of a three-column table.