Ergonomics, also known as Human Factors or Human Factors Engineering (HFE), is the scientific discipline concerned with the understanding of interactions among humans and other elements of a system, and the profession that applies theory, principles, data, and methods to design in order to optimize human well-being and overall system performance. It involves the application of psychological and physiological principles within the domains of engineering and design, encompassing products, processes, and systems. The primary goals of human factors engineering are to reduce human error, increase productivity and overall system performance, and enhance safety, health and comfort. A specific focus of this field is the interaction between the human and other sociotechnical elements.

The field applies theories, principles and data from a variety of primary or pure disciplines, such as psychology, sociology, engineering, biomechanics, industrial design, physiology, sociotechnical systems, human-computer interaction, anthropometry, interaction design, visual design, user experience, and user interface design. Human factors research employs methods and approaches from these and other knowledge disciplines to study human behavior and generate data relevant to human-system interface technology to achieve previously stated goals. In studying and sharing learning on the design of equipment, devices, and processes that fit the human body and its cognitive abilities, the two terms, "human factors" and "ergonomics", are essentially synonymous as to their referent and meaning in current literature.