Intentionality is the power of minds to be about something: to represent or to stand for things, properties and states of affairs. Intentionality is primarily ascribed to mental states, like perceptions, beliefs or desires, which is why it has been regarded as the characteristic mark of the mental by many philosophers.

In knowing, the mind is said to “intend” or “tend toward” its object, and a thing as known, or in the knowing mind, has “intentional being.” Intention may mean either the mind knowing or the knowledge itself, analogous to the use of perception for the act of perceiving or for the thing perceived.

Intentions are mental states that involve action plans to which the agent has committed themselves. As action plans, they can guide behavior. The action plan constitutes the content of the intention while the commitment is the agent's attitude towards this content.