A Question time in a parliament occurs when members of the parliament ask questions of government ministers (including the prime minister), which they are obliged to answer. It usually occurs daily while parliament is sitting, though it can be cancelled in exceptional circumstances. Question time originated in the Westminster system of the United Kingdom, and occurs in other countries, mostly Commonwealth countries, who use the system.
In practice, the questions asked in question time are usually pre-arranged by the organisers of each party; although the questions are usually without notice. Questions from government backbenchers are either intended to allow the Minister to discuss the virtues of government policy, or to attack the opposition. A typical format of such a government backbencher's question might be "Could the Minister discuss the benefits of the government's initiative on <issue>, and is the Minister aware of any alternative policies in this area?"
Question time is an institution in the Commonwealth Parliament and in all state parliaments. Questions to government ministers normally alternate between government members and the opposition, with the opposition going first. Questions of ministers are generally asked by their counterpart shadow ministers in the opposition, and are always asked by backbenchers on the government side. In the House of Representatives, the first question is usually asked of the Prime Minister by the Leader of the Opposition. Similar arrangements apply in the Senate. To accommodate the distribution of ministers between both chambers, ministers also take on representative roles, answering questions relating to portfolios that are not their own because the responsible minister sits in the other chamber. This allows questioners to ask questions about any government portfolio in either chamber. This normally includes the Leader of the Government in the Senate representing the Prime Minister in response to questions asked by senators about general government policy. Sometimes a government Minister will arrange for a government backbencher to "ask" a question, commonly called a Dorothy Dixer, to enable the Minister to make a political speech or otherwise score political points.