Definition
The EOP, overseen by the White House Chief of Staff, has traditionally been home to many of the President's closest advisers.
While Senate confirmation is required for some advisers, such as the Director of the Office of Management and Budget, most are appointed with full Presidential discretion.
The individual offices that these advisors oversee have grown in size and number since the EOP was created. Some were formed by Congress, others as the President has needed them — they are constantly shifting as each President identifies his needs and priorities, with the current EOP employing over 1,800 people.