Types of Committees
Committees often serve several different functions:
Governance: in organizations considered too large for all the members to participate in decisions affecting the organization as a whole, a committee (such as a Board of Directors or "Executive Committee") is given the power to make decisions, spend money, or take actions. Some or all such powers may be limited or effectively unlimited. For example of the later case, the Board of directors can frequently enter into binding contracts and make decisions which once taken or made, can't be taken back or undone under the law.
Coordination: individuals from different parts of an organization (for example, all senior vice presidents) might meet regularly to discuss developments in their areas, review projects that cut across organizational boundaries, talk about future options, etc. Where there is a large committee, it is common to have smaller committees with more specialized functions - for example, Boards of Directors of large corporations typically have an (ongoing) audit committee, finance committee, compensation committee, etc. Large academic conferences are usually organized by a co-ordinating committee drawn from the relevant professional body.
Research and recommendations: committees are often formed to do research and make recommendations on a potential or planned project or change. For example, an organization considering a major capital investment might create a temporary working committee of several people to review options and make recommendations to upper management or the Board of Directors. Such committees are typically dissolved after issuing recommendations (often in the form of a final report).
Tabling: as a means of public relations by sending sensitive, inconvenient, or irrelevant matters to committees, organizations may bypass, stall, or disacknowledge matters without declaring a formal policy of inaction or indifference.