The three branches of the federal government — legislative, executive, and judicial — operate within a constitutional system known as "checks and balances." This means that although each branch is formally separate from the other two, the Constitution often requires cooperation among the branches. Federal laws, for example, are passed by Congress and signed by the President. The judicial branch, in turn, has the authority to decide the constitutionality of federal laws and resolve other disputes over them, but judges depend upon the executive branch to enforce court decisions.
Federal Courts & Congress
The Constitution gives Congress the power to create federal courts other than the Supreme Court and to determine their jurisdiction. It is Congress, not the judiciary, that controls the type of cases that may be addressed in the federal courts.
Congress has three other basic responsibilities that determine how the courts will operate. First, it decides how many judges there should be and where they will work. Second, through the confirmation process, Congress determines which of the President's judicial nominees ultimately become federal judges. Third, Congress approves the federal courts' budget and appropriates money for the judiciary to operate. The judiciary's budget is a very small part — substantially less than one percent — of the entire federal budget.
Federal Courts & the Executive Branch
Under the Constitution, the President appoints federal judges with the "advice and consent" of the Senate. The President usually consults senators or other elected officials concerning candidates for vacancies on the federal courts. The President's power to appoint new federal judges is not the judiciary's only interaction with the executive branch. The Department of Justice, which is responsible for prosecuting federal crimes and for representing the government in civil cases, is the most frequent litigator in the federal court system. Several other executive branch agencies affect the operations of the courts. The United States Marshals Service, for example, provides security for federal courthouses and judges, and the General Services Administration builds and maintains federal courthouses.