A more thorough explanation:

The Federal Rules of Civil Procedure are a set of 86 rules that govern how civil cases are handled in U.S. federal courts. These rules cover procedural law, which is different from substantive law, and are designed to ensure that every action and proceeding is determined justly, speedily, and inexpensively.

For example, the rules cover:

• How to file a complaint or answer
• When and how to make a motion to dismiss a case
• How to join multiple parties or claims into one case
• How to conduct discovery, which is the process of gathering evidence
• How to conduct a trial
• How to obtain injunctive relief, which is a court order to stop or start doing something
• How to issue judgments and orders

It's important to note that the Federal Rules of Civil Procedure only apply to civil cases in federal court. They do not apply to criminal cases, state court cases, or appeals.

The rules were created in 1938 by the U.S. Supreme Court, which was given the power to do so by the Rules Enabling Act of 1934. The rules have been amended many times since then, but the core principles of ensuring just, speedy, and inexpensive determinations of civil cases remain.

Overall, the Federal Rules of Civil Procedure are an important part of the U.S. legal system, as they help ensure that civil cases are handled fairly and efficiently.