Legislative chambers are the parts of a government responsible for making laws. Most countries have a system with either one chamber, known as a unicameral system, or two chambers, called a bicameral system. Each chamber has its own members, who are elected or appointed, and they debate and vote on proposed laws. In a bicameral system, the two chambers often have different roles and powers. For example, in the United States, the two chambers are the House of Representatives and the Senate. Each chamber must approve a bill for it to become law, ensuring a system of checks and balances in the legislative process.