When The operation of two separate and distinct in the court system is referred in the US is referred as what?

The operation of two separate and distinct court systems in the United States is referred to as "dual court system." This system comprises federal courts and state courts, each having its own jurisdiction and authority. Federal courts handle cases involving Federal Laws and constitutional issues, while state courts deal with matters under state laws. This structure allows for a division of legal responsibilities and ensures a broader access to justice.