A psychologist deals with the workings of the human mind, in areas like cognition, behaviour, and affect.
People don't need to have a mental problem to see a psychologist. Psychologists actually have strategies to make even healthy people function better like how to prepare for problems that may arise from build-up of everyday living that may have a serious impact of their lives like relationship difficulties and dependencies on people or substances.
Unlike psychiatrists psychologists do not prescribe medication, however psychological help and treatment of anxiety and depression have been successful without having to resort to drugs and medication.
Psychological assessment is compiling data from results of varying test involving areas such as personality, ability and skills, intelligence, interests or attitudes, likes and dislikes, fears as well as information from personal interviews. External data about personal, occupational, or medical history and interviews with people who have had intimate dealings with the person like parents, spouses, teachers, or previous therapists or physicians can also be used.
A psychologist may have a few specialties they deal with. If they like to work with children they focus on child psychology, if they like to work with reforming criminals they focus on criminal psychology.
Today government and some businesses have employees undergo psychological tests relevant to the field of work they are in. This is to determine the suitability of the applicant in respect to the ability to fit into the role by satisfying the psychological requirements faced by the employee in carrying out their duties.