In many parliaments and other similar assemblies, seating is typically arranged in banks or rows, with each political party or caucus grouped together. The spokespeople for each group will often sit at the front of their group, and are then known as being on the frontbench (or front bench) and are described as frontbenchers. Those sitting behind them are known as backbenchers. Independent and minority parties sit to the side or on benches between the two sides, and are referred to as crossbenchers.
In the British House of Commons, the Government frontbench is traditionally called the Treasury bench (HM Treasury is the oldest government department). The government frontbench is on the right hand side as seen by the Chairman (typically the Speaker of the House of Commons or the Lord Speaker), and is occupied by Government ministers. The opposition frontbench is occupied by shadow ministers, of which the most senior form the Shadow Cabinet.
While backbenchers are referred to in the Canadian House of Commons (and the provincial legislatures), the front seats on the government side are reserved for cabinet ministers. Front row members are not referred to as frontbenchers, but as cabinet ministers. Some "frontbenchers" actually sit in the centre of the second row, so as to be seen directly behind the party leader during Question Period (and thus, in the television frame).
The same arrangement exists for each provincial legislature and territorial legislature of Yukon. In the case of Nunavut and Northwest Territories where Consensus government with non-partisan makeup where ministers sits amongst regular members.