Definition
Bicameralism is the structuring of a legislature into two distinct chambers, each with its own membership, rules, and basis of representation. In the United States, Congress is bicameral: it consists of the House of Representatives and the Senate.
A bill becomes law only if both chambers pass identical text. This requirement makes lawmaking slower and more deliberative, since two differently constituted bodies must reach the same conclusion.
Why it matters
How it works
The House is apportioned by population, so larger states hold more seats, and members serve two-year terms tied closely to public opinion. The Senate gives every state two seats regardless of size, with six-year staggered terms meant to encourage a longer view.
Because the two chambers answer to different constituencies and timelines, they often disagree. Conference committees and repeated votes reconcile competing versions of a bill, and only the agreed text is sent to the president.