Agent - Wikipedia

An agent is an autonomous entity with an ontological commitment and agenda of its own.

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.

In law an agent is a person authorized to act for another, with delegated authority, such as a person holding a power of attorney.

Example: real estate agent[?], secret agent

The term is also used in computer science to refer to pieces of autonomous, or semi-autonomous, computer software.

Examples: user agent[?], mail transfer agent, software agent[?], SNMP agent[?], DAML.

To be considered a bonafide agent, the software must exhibit the behavioural qualities of agenthood. A mail transfer agent for example decides when to transfer and deliver the mail, and does so asynchronously and independently from the behaviours of other agents in the system.

Agents generally --and including some software agents-- have the ability to learn and to reason, logically or otherwise. They may discover facts and rules about the world or about others and may assess and argue these truths and may alter their ontology.