The term originated in philosophy.
Each agent possesses the ability to act autonomously; this is an important distinction because a simple act of obedience to a command does not qualify an entity as an agent.
An agent may interact or negotiate with its environment and/or with other agents. It may make decisions, such as whether to trust and whether to cooperate with others.
Types of Agents
The term agent is also used for sentient programs found in the Matrix that battle the humans fighting for freedom.