Activity may refer to: * Action (philosophy), in general * Human activity: human behavior, in sociology behavior may refer to all basic human actions, economics may study human economic activities and along with cybernetics and psychology may study their modulation *

Recreation Recreation is an activity of leisure, leisure being discretionary time. The "need to do something for recreation" is an essential element of human biology and psychology. Recreational activities are often done for enjoyment, amusement, or plea ...

, or activities of leisure * The Aristotelian concept of

energeia In philosophy, potentiality and actuality are a pair of closely connected principles which Aristotle used to analyze motion, causality, ethics, and physiology in his ''Physics'', ''Metaphysics'', ''Nicomachean Ethics'', and ''De Anima''. The ...

, Latinized as ''actus'' * Activity (UML), a major task in Unified Modeling Language * ''Activity'', the rate of catalytic activity, such as enzyme activity ( enzyme assay), in physical chemistry and enzymology *

Thermodynamic activity In chemical thermodynamics, activity (symbol ) is a measure of the "effective concentration" of a species in a mixture, in the sense that the species' chemical potential depends on the activity of a real solution in the same way that it would depe ...

, the effective concentration of a solute for the purposes of mass action *

Activity (project management) In project management, a task is an activity that needs to be accomplished within a defined period of time or by a deadline to work towards work-related goals. It is a small essential piece of a job that serves as a means to differentiate variou ...

* Activity, the number of radioactive decays per second *

Activity (software engineering) Activity diagrams are graphical representations of workflows of stepwise activities and actions with support for choice, iteration and concurrency. In the Unified Modeling Language, activity diagrams are intended to model both computational and ...

Activity (soil mechanics) The Atterberg limits are a basic measure of the critical water contents of a fine-grained soil: its shrinkage limit, plastic limit, and liquid limit. Depending on its water content, soil may appear in one of four states: solid, semi-solid, plast ...

* , an aircraft carrier of the Royal Navy * "Activity", a song by Way Out West from ''

Intensify ''Intensify'' is the second studio album by English electronic music duo Way Out West, released on 20 August 2001 by Distinct'ive Records. The album was marked by a move from the defunct Deconstruction Records label to Distinctive, and a chang ...

'' * Cultural activities, activities referred to culture.

See also