Humans, robots, and programmes all qualify as agents under this definition. A human, for example, is an agent since it has sensors (such as the eyes) and actuators (such as the hands, which are also sensors) and interacts with the environment (the world).
A percept (or perception) comprises all of the agents' perceptual inputs. Depending on the agent, the exact definition of the percept varies. In the case of a human, the percept is made up of all perceptual inputs from all of the human sense organs (eyes, ears, tongue, skin, and nose). When a robot is just equipped with a camera, the percept is limited to the camera frame (at a certain point in time). A percept sequence is a list of percepts in order.
Anything that has an impact on the environment is considered an activity. An action for a legged robot, for example, maybe "go ahead."
The agent function (shown in the picture above as a white box with a black question mark) chooses an action, also known as a policy.
The agent's intelligence or intellectual skills are heavily influenced by the agent's role, distinguishing it from other agents.