Business law, also called commercial law or mercantile law, the body of rules, whether by convention, agreement, or national or international legislation, governing the dealings between persons in commercial matters.
Business law falls into two distinctive areas: (1) the regulation of commercial entities by the laws of company, partnership, agency, and bankruptcy and (2) the regulation of commercial transactions by the laws of contract and related fields.
In civil-law countries, company law consists of statute law; in common-law countries it consists partly of the ordinary rules of common law and equity and partly statute law. Two fundamental legal concepts underlie the whole of company law: the concept of legal personality and the theory of limited liability. Nearly all statutory rules are intended to protect either creditors or investors.