In a sense, every career is a psychology career. Whether you're a salesman, a schoolteacher, or a sports coach, to be effective—and especially to advance in your career—you often need a fine-tuned understanding of what motivates people.
Psychology itself is hardly a monolithic field. Careers that require formal training in psychology are incredibly varied: Providing clinical psychotherapy is very different from conducting research in a laboratory. People who work in psychology-related fields may be trained as psychologists, social workers, school counselors, researchers, or medical doctors.