Agent

An agent is an entity that acts or exerts power to produce an effect.

An intelligent agent is an agent that percieves its environment, take actions autonomously in order to achieve goal, and may improve its performance with Learning or acquiring Knowledge.

Reflex Agent Diagram This diagram is reminiscent of the OODA Loop

Agent-Based Model

An agent based model (ABM) is a computational model for simulating the actions and interactions of autonomous agents.