The main task of controlling as a part of the corporate management system is the planning, steering, and monitoring of all company areas. In practical business, controlling has become indispensable. Companies without effective controlling run the risk of overlooking existential threats and also miss the opportunity to improve their competitiveness. In this new textbook, Peter Lorson, Reiner Quick, and Hans-Jürgen Wurl explain the tasks, sub-areas, and objectives of controlling. After a fundamental introduction, strategic controlling and operational controlling are presented in detail. This is followed by a look at controlling from an organizational perspective and a discussion of future prospects.