The Three Categories of Law in Today's Legal System

We can think about modern-day law in three main ways:

1. Substantive criminal law is composed of legal statutes that define certain behaviors as criminal in nature, and that outline the punishment for those offenses.  In other words, these systems of laws (at the state and Federal level) outline the “substance” of the law.  The main purpose of substantive law is to deter criminal behavior and punish offenders such that social order can be maintained.
    
2. Procedural law is associated with the process in place to deal with citizens who break the law and is concerned wit such issues as due process, rules of evidence, and all other matters that are considered to be the rights of U.S. citizens under several amendments contained in the nation’s constitution (see a discussion on this below).
    
3. Civil law is not concerned with government action against a citizen, but with actions between private parties (individuals and organizations).  We are most familiar with civil law in terms of wills, contracts, torts (the law of personal injury).