-Executive Privilege is the right claimed by the U.S. president and other officials of the executive branch of the U.S. government to withhold from Congress, the courts or people information that has been requested or subpoenaed.
-Executive privilege also can be invoked to prevent executive branch officials or employees from testifying in U.S. congressional hearings.
-Presidents have exercised executive privilege in cases that involve national security and those that involve executive branch communications.
-Presidents most often claim executive privilege to protect sensitive military or diplomatic information.
-The right of executive privilege is not directly granted to the president in the Constitution. Instead, it has historically been considered a right implied by the constitutional principal of separation of powers between the three branches of the U.S. government: executive, legislative, judicial.