The upper house of Congress is called the Senate. Congress has two groups of legislators, the Senate and the House of Representatives. The Senate is considered the upper house because its members have unique powers and responsibilities, such as confirming Cabinet secretaries and federal judges.
There are 100 members in the Senate, two from each state. The House of Representatives, by contrast, has 435 voting members.
Senators are elected by the voters in their state for 6-year terms. Senators must be at least 30 years old, must be residents of the state that they represent and must have been residents of the United States for at least 9 years.