Bicameral legislature
Bicameral refers to a division in two in the legislature of a nation's government. Generally, the divisions are referred to as the two "houses" of the legislature. Typically, one house is more numerous than the other, and the more numerous house is known as the lower house and the less numerous is known as the upper house. The lower house is also typically elected by the people of the country, while the upper house may or not be. The upper house may have other distinguishing features that differentiate it from the lower house.
Examples
In the United States, the Congress is comprised of the House of Representatives and the Senate. The House of Representatives, the lower house, consists of 435 members, elected by the people. Representatives are apportioned to each of the states in proportion to the state populations. The Senate, the upper house, consists of two members from each state, currently 100 members. Originally, Senators were selected by the states, but in 1912, the Senate was changed to popular election of members.
In the United Kingdom, the Parliament is comprised of the House of Commons and the House of Lords. The House of Commons, the lower house, consists of 646 members elected by the people, each member representing one district. The House of Lords, the upper house, is comprised of members of the peerage and the bishopric, and in 2007, had over 750 members. In 2007, serious efforts were underway to change the House of Lords to an elected body, or to abolish it completely.
In Canada, the Parliament is comprised of the House of Commons and the Senate. The House of Commons, again the lower house, has 308 members elected by the people. The 105 members of the Senate are recommended by the House of Commons and are appointed for life, or until the age of 75.