About Congressional Hearings:
"A hearing is a meeting or session of a Senate, House, joint, or special committee of Congress, usually open to the public, to obtain information and opinions on proposed legislation, conduct an investigation, or evaluate/oversee the activities of a government department or the implementation of a Federal law. In addition, hearings may also be purely exploratory in nature, providing testimony and data about topics of current interest. Most congressional hearings are published two months to two years after they are held." [GPO]
Note: The decision to publish a committee hearing is left up to the committee. Some hearings remain unpublished, but they should eventually find their way to the National Archives. Some of these hearings were subsequently made available on microfilm and many are included in Proquest Congressional. See U.S. Government Documents: A Finding Guide for more information.
About House and Senate Reports:
"Congressional reports originate from congressional committees and deal with proposed legislation and issues under investigation.
--House and Senate Reports: Reports of congressional committees concerning proposed legislation or containing findings on matters under investigation.
--Senate Executive Reports: Reports of the Committee on Foreign Relations relating to treaties between the United States and foreign nations which have been submitted to the U.S. Senate for ratification, or are reports of various Senate committees regarding nomination of individuals." [GPO]