XML Catalog
An XML Catalog maps a system ID or a URI reference for a resource
(stored either remotely or locally) to a local copy of the same resource. Whenever XML
processing relies on external resources (such as referenced schemas and stylesheets), the use of
an XML Catalog becomes a necessity when Internet access is not available or the
connection is slow.
Oxygen XML Developer Eclipse plugin includes default global catalogs as well as default catalogs for each of the built-in frameworks, and you can also create your own. Oxygen XML Developer Eclipse plugin uses these XML Catalogs to resolve references for document validation and transformations. For more information, see Working with XML Catalogs.