What is the basic definition of bureaucracy? Who was one of the primary theorists on how bureaucracies were to function? Explain the primary functions on how a bureaucracy is supposed to work, according to the theorist.

The bureaucracy has been colloquially referred to as the "permanent government." It consists of officials and government employees charged with the day to day administration of the affairs of state and the implementation of the policies developed by elected political leaders. In contrast to elected political leaders, the bureaucracy remain at their posts through the passage of new governments. They are not directly responsible to the electorate and are, ideally, chosen through a meritocratic process.
The German sociologist Max Weber (1864–1920) was an early theorist on the nature of bureaucracies. According to him, the model bureaucracy will have several hallmarks, including: specialization of responsibilities, evaluation on the basis of productivity, a clearly defined set of goals, formal and objective rules, a division of labor, and a chain of command.
In the U.S. system of governance, the so-called "permanent government"—it has been claimed—has developed beyond the bureaucracy to include also staff members of standing congressional committees, as well as outside organizations and lobbyists. This triumvirate is referred to as the "iron triangle." There may be benefits in such an arrangement in that it encourages further professionalization and specialization, however, it also tends to remove the bureaucracy further from its ultimate role of being the implementer of policy developed by elected political leaders and into a hybrid role that finds it advocating and advancing policy as well.