A more thorough explanation:

The Rules Enabling Act of 1934 is a law passed by the United States Congress that gave the Supreme Court the authority to create rules for how federal courts should operate. These rules include procedures and evidence that should be used in court cases. However, these rules cannot change any substantive rights that people have.

For example, if a person has the right to a fair trial, the Supreme Court cannot create a rule that would take away that right. But they can create rules that explain how evidence should be presented in court or how a trial should be conducted.

The Rules Enabling Act of 1934 was important because it helped to standardize the way that federal courts operate. Before this law was passed, each court had its own set of rules, which could be confusing for lawyers and judges who worked in different courts. By creating a set of rules that applied to all federal courts, the Supreme Court made it easier for everyone to understand how the courts should operate.