– intentional, purposive, conscious and subjectively meaningful sequences of actions.
- Arts – vast subdivision of culture, composed of many creative endeavors and disciplines. The arts encompasses visual arts, literary arts and the performing arts.
- Law enforcement
- Applied science – application of scientific knowledge transferred into a physical environment. Examples include all fields of engineering.
- Formal science – branch of knowledge with many subbranches which are concerned with formal systems. Unlike other sciences, the formal sciences are not concerned with the validity of theories based on observations in the real world, but instead with the properties of formal systems based on definitions and rules.
- Natural science – major branch of science that tries to explain and predict nature's phenomena, based on empirical evidence. In natural science, hypotheses must be verified scientifically to be regarded as scientific theory. Validity, accuracy, and social mechanisms ensuring quality control, such as peer review and repeatability of findings, are among the criteria and methods used for this purpose.
- Social science – study of the world and its cultures and civilizations. Social science has many branches, each called a "social science".
- Sports – organized, competitive, entertaining, and skillful activity requiring commitment, strategy, and fair play, in which a winner can be defined by objective means. Generally speaking, a sport is a game based in physical athleticism.
- Transport – the transfer of people or things from one place to another.
- Underwater diving – practice of people descending below the water's surface to interact with the environment.
- War – state of armed conflict between states, governments, societies and informal paramilitary groups, such as mercenaries, insurgents and militias. It is generally characterized by extreme violence, aggression, destruction, and mortality, using regular or irregular military forces.
Impact of human activity