Law

When people talk about the “law” of the United States, they are probably referring to the law system it has. The U.S. uses a common law system, which means that it tends to rely on the decisions made by judges on cases that have come to trial; The compilation of these decisions is called case law (Note: other countries, such as Japan, have a civil law system, which relies on codes that explicitly provide the rules that judges must follow in order to come to a decision, and so such decisions are often not subject to individual interpretation).

“Law” can also mean “state law,” which includes common law and statutes and regulations. The same is true for “federal law.”

Yet another distinction is that between procedural law and substantive law.

Additionally, international law is “composed only of those rules that States universally abide by, or accede to, out of a sense of legal obligation and mutual concern.”