There are several types of parliamentary committee, depending on their purpose and their composition:
Joint committees are committees whose members are drawn from both the House of Representatives and the Senate, or the equivalent State chambers. Despite their membership coming from both houses, all joint committees are administered by and report back to a specific House of Parliament. Joint committees can be standing or select committees (see below). The Commonwealth Parliament currently has 14 joint committees, 10 of which are administered by the House of Representatives and four by the Senate. These joint committees are investigating a wide range of issues, including public accounts, a constitutional amendment to recognise indigenous people, migration, treaties, electoral reform, law enforce and intelligence and security.
Standing committees exist for the duration of the parliament (that is, the elected government) and are established to oversee and investigate specific issues or areas. Many standing committees are perpetual and align closely with the various ministerial portfolios, such as the House Standing Committee on Education and Training. Other committees deal with internal or procedural issues, such as the Senate Standing Committee on Legal and Constitutional Affairs. Both these committees have existed since the mid-1980s.
Select committees are formed only to investigate and advise the parliament on a particular issue. Once the committee has tabled its findings or report, then it is disbanded. In March 2009 the Senate formed a Select Committee on Climate Policy to examine legislative responses to climate change. This committee tabled its report in mid-June 2009 and was then dissolved.
Estimates committees meet regularly to examine and scrutinise expenditure. These committees are not so much concerned with changing or improving laws, but more in ensuring that government is accountable with its budgeting and its use of public money.
The parliament can refer any bill to a committee for scrutiny and further investigation. This may be to obtain more information about the costings, the legal implications or the social ramifications of the bill. In doing so a committee can obtain legal advice, seek expert opinion, consult witnesses and receive public submissions. Committees are therefore an important source of information about how a bill might function if it was to become law.