The Function, Evolution, and Historical Development of the Law: Martha M. Rumore
There are three branches of government: executive, legislative, and judicial. Legislatures create statutory law by enacting bills which become laws. The judiciary makes common law, which is found in court decisions. However, it is impossible for the legislature to make all the necessary rules or for the judicial branch to handle all of the cases. Certain fields require nonlegal expertise. Therefore, Congress created the administrative agencies, often referred to as the fourth branch of government, which create administrative law. Agencies act like courts or legislatures by making rules or deciding cases. Administrative agencies may be called commissions, boards, bureaus, divisions, or agencies.