House and Senate Bills are the usual form in which legislation is proposed to the U.S. Congress. Although thousands of bills may be introduced, few are enacted into law, and many do not receive serious consideration. If not enacted into law, a bill "dies" at the end of a Congress.
Generally, the citation to a Bill follows the pattern:
[Congress number] [Chamber abbreviation] [Bill number]
101 H.R. 44 is the citation for House Bill 44 in the 101st Congress
101 S. 1054, similarly, is the 1,054th Senate Bill introduced during the 101st Congress