Industrial/Organisational (I/O) psychology is a specialised branch of psychology that applies psychological principles, theories, and research methods to understand human behaviour in workplace settings. It focuses on improving employee performance, well-being, organisational effectiveness, and the relationship between individuals and organisations. The field has expanded significantly due to changes in technology, globalisation, workforce diversity, and evolving organisational structures. One major field of I/O psychology is personnel psychology, which deals with the recruitment, selection, placement, training, and evaluation of employees. It applies psychological assessment techniques such as aptitude tests, personality tests, and interviews to identify suitable candidates for specific jobs. Personnel psychologists also study job analysis, performance appraisal methods, employee competencies, and career development to ensure that individuals are matched effectively with organisational roles. Another important field is organisational psychology, which focuses on understanding employee behaviour within organisations. It examines topics such as motivation, job satisfaction, leadership, communication, group dynamics, organisational culture, and employee attitudes. Organisational psychologists study how workplace environments influence productivity and employee commitment. They develop strategies to improve teamwork, reduce conflicts, enhance leadership effectiveness,