Controlling can be seen as a part of business management, that supports the agents involved in a target process in the fields of control, planning, management and coordination.
The general goal would be to give constant support to the current management for the preparation and making of decisions. Controlling is often used in conjunction with planning and approval of company expeditures.
In small and medium-sized businesses controlling is usually taken on by a number of people or by the company directors. In larger businesses these tasks are increasingly done by an autonomous controller.