In the United States, a congressman or congresswoman is a member of the House of Representatives, which is one of the two houses of the Congress.
The United States Congress is made up of the Senate and the House of Representatives, which is a body of elected officials who represent individual districts in their home states. The job of these House members is basically to vote on and pass laws. While each state gets two Senators, the number of House members is determined by state population, and their term is two years long.