One means of classifying the law is to divide it into matters of public law and matters of private law. Public law includes constitutional law, administrative law, and criminal law. Public law provides a major portion of the legal environment of business. Private law encompasses those legal problems and relationships which exist between individuals, as contrasted with those in which society is involved. Private law is traditionally separated into the law of contracts, the law of torts, and the law of property.
Another important classification or distinction in law is the one between substance and procedure. Substantive law defines the legal relationship of people with other people, or as between them and the state. Procedural law deals with the method and means by which substantive law is made and administered. In other words, substantive rules of law define rights and duties, while procedural rules of law provide the machinery for enforcing those rights and duties.
Every social institution has rules by which it conducts its affairs or “proceeds.” There are rules of law relating to legislative procedure which govern the steps that must be taken for a statute to be valid. Judicial procedures involve the method of conducting lawsuits, appeals, and the enforcement of judgements. The rules for conducting civil trials are different from those for criminal trials. For example, each party may call the other party to the witness stand for cross-examinationin a civil trial, but the defendant may not be required to testify in a criminal case. Procedural problems sometimes arise concerning papers filed in lawsuits, the admission ofevidence, and various other techniques involved in trying the case. A classification similar to that of public versus private contrasts civil law cases with criminal cases. For administrative purposes courts usually separate criminal actions from other lawsuits, with the latter known as civil cases.