Administrative agencies come in many forms and sizes. This is due, in large part, to the fact that agencies are created to confront an array of problems. In addition, agencies exist at all levels of government. The primary focus of this book is federal administrative agencies, although many of the principles discussed herein apply to all agencies. Administrative agencies have many names, including departments, com-missions, bureaus, councils, groups, services, divisions, and agencies. Agencies often also have subunits bearing these names.

Not all governmental entities are agencies. Courts and legislatures are not agencies. They are constitutionally created branches of government. Therefore, administrative law principles do not usually apply to those bodies. Not all agencies are of great concern to the study of administrative law. The study of administrative law focuses on agencies whose actions affect the rights of individuals, also known as civil rights.