The breadth of psychology makes it difficult to define or even summarise in a few lines. There are psychologists who study the brain and nervous system. Others study basic mental functions like perception, memory and thought.
Some psychologists study the development of children, while others study social groups.
This may seem confusing but the good news is that virtually everyone can find something in psychology that is of interest to them. Psychology has links to the natural sciences, the social sciences and the arts. Students who wish to gain an overview of psychology would be well advised to look at one of the many introductory textbooks on the subject. McGraw Hill 2. There are several differences but one of the most important is the training that psychologists, psychiatrists and psychoanalysts have.