Within the two main categories are many further types of psychologists as reflected by the 56 professional classifications recognized by the APA, including clinical, counseling, and school psychologists. Such professionals work with persons in a variety of therapeutic contexts. People often think of the discipline as involving only such clinical or counseling psychologists. While counseling and psychotherapy are common activities for psychologists, these applied fields are just two branches in the larger domain of psychology. There are other classifications such as industrial, organizational and community psychologists, whose professionals mainly apply psychological research, theories, and techniques to "real-world" problems of business, industry, social benefit organizations, government, and academia.