The Industrial and Organizational Psychology is defined as “the branch of psychology that makes use of psychological theories and principles to organizations.” It is abbreviated as I/O Psychology. The main area of concern of an I-O psychologist is to resolve issues such as increasing work-place productivity, ensuring proper physical and mental well-being of the people working within the industry, etc.To find appropriate solutions to the issues, an industrial and organizational psychologist is required to perform a variety of tasks such as conducting leadership training, carrying out an evaluation of companies, studying the attitudes and behavior of the workers employed in the companies.The Industrial and Organizational Psychology is comprised of the two sides namely, the Industrial and the Organizational side of psychology, both of which focus on entirely different perspectives however they are not very different from each other in terms of their applications, their goals and their topics of interest.The emergence of World War I and World War II helped in making significant changes in the field of Industrial and Organizational Psychology. After the breakout of World War II, the APA began to look strictly into the proceedings of the I/O Psychology and formulated the Division 14, Industrial and Business Psychology.The I/O Psychologist are trained to perform several qualitative and quantitative studies and tests on the individual working within an industry or organization in order to provide appropriate solutions to their problems which are characterized by the professional practice domains of an I/O psychologist.To help with keeping the psychological matters of a company under control of the industrial and organizational branch of psychology comes into effect.