Report definition files include a set of instructions that describe layout, and a query that retrieves report data at run time. Report definitions are created in Report Designer and are realized at run time as a processed report. Although a report definition can be complex, at a minimum it specifies a query and other report content, report properties, and report layout.
A report definition is composed of XML elements that conform to an XML grammar created for Reporting Services Report Definition Language (RDL). RDL describes the XML elements, which encompass all possible variations that a report can assume.
About Report Definitions and .rdl Files
Report definitions can exist both as files on a file system and as report items in a report server.
On the file system, report definitions have a file extension of .rdl. Report authors create .rdl files using an authoring tool such as Report Designer. After an .rdl file is created, it is published to a report server, where it becomes an item stored in a report server. An .rdl file can also be uploaded from the file system into the report server, using upload features in Report Manager.
On a report server, reports are retrieved from a report server database and presented to users and applications as items in a report server folder. Items managed and stored by a report server are distinct from files on a file system.
For more information about report server folder hierarchy, see Report Server Folder Namespace. For more information about authoring reports and report definitions, see Designing and Creating Reports and Report Definition Language.