A Bicameral system of government is one where there are two legislative or parliamentary chambers. The word comes from the Latin "bi" (meaning two) and "camera" (meaning chamber). In most cases they have different numbers of members. The smaller legislature is often called the "upper house" or "senate" and the larger is called the "lower house", and sometimes also called by another name such as "assembly" or "commons". For legislation to be passed, bicameral legislatures normally need a majority of members of both chambers to vote for the legislation.
Experts sometimes point out that often deadlocks occur in this kind of system. This can make it harder to pass laws. But others point out the checks and balances this system maintains. This prevents laws from being passed that favor a certain political faction, the government or group of people.