The two houses of Congress are called the House of Representatives and the Senate. Together, they form the legislative branch of the United States government.
The House of Representatives
In the House of Representatives, the number of representatives per state is determined by the state's population. Larger states have more representatives than smaller states, but representatives are elected by a smaller portion of the state than senators. Representatives are elected for 2-year terms, and members of the House focus more on taxes and revenue. The majority party in the House of Representatives is usually highly favored.
Every state has two senators, so all states are equally represented in the Senate. However, senators represent much larger portions of their states than representatives. Once elected, senators serve 6-year terms. The focus in the Senate is on foreign and national policy.