Parliamentary select committees of the United Kingdom

The parliamentary select committees of the United Kingdom are committees formed by members of the British Parliament. Members can be appointed from the House of Commons (like the Foreign Affairs Select Committee), from the House of Lords (like the Delegated Powers and Regulatory Reform Committee), or as a "Joint Committee" drawn from both (such as the Joint Committee on Human Rights).
The House of Commons select committees are responsible for overseeing the work of government departments and agencies. Committees of the House of Lords look at general issues; for example, the constitution is considered by the Constitution Committee, and the economy is considered by the Economic Affairs Committee. 
Background.
Committees may exist as "sessional" committees (that is, be nearly permanent), or as "ad-hoc" committees with a specific timeline by which to complete their work, after which they stop existing, such as the recent Lords Committee on Public Service and Demographic Change.
Both Houses have their own committees to review drafts of European Union directives: the European Union Committee in the House of Lords, and the European Scrutiny Committee in the House of Commons.