active

Active is an adjective that describes something that is in motion, functioning, or participating. It refers to a state of being engaged or involved rather than passive or idle. In various contexts, active can describe physical movement, mental engagement, or operational status.

In physical terms, active describes something that is moving or exerting energy, such as an active volcano or an active participant in sports. In technology and computing, active refers to systems or applications that are currently running or in use. An active window on a computer screen, for example, is the one currently being used.

In health and fitness contexts, an active lifestyle involves regular physical exercise and movement. In military or security contexts, active duty refers to personnel who are currently serving in a capacity that requires their immediate presence and engagement. The term can also describe grammatical voice, as in active voice where the subject performs the action, as opposed to passive voice where the subject receives the action.