An AI agent is like a regular software agent that independently performs an action based on an external event, except that AI agents are part of an AI system. AI agents are extremely versatile. Not only can they access external sources such as a database or website, but they can learn by trial and error. The key to any agent, AI or otherwise, is that it can act on its own after an event occurs, which can be a query or message or even the time of day. See
agent.
AI Agent vs. AI System
AI scientists are busy developing the next breakthrough formula, and like a lot of terminology in the tech world, terms are made up by different groups without regard to consensus.
The terms AI agent and AI system are often used synonymously, but AI developers may define them differently. However, there is usually general agreement that an AI agent falls within an AI system, the latter being the more comprehensive of the two, and there can be many agents within a system. However, there are articles about AI agents with little mention of an AI system. In addition, an AI system is commonly called just an "AI." For example, "an AI does this" or "an AI does that."
Stay tuned! Eventually, the terminology may work its way out. Two examples of an excessive number of names for the same thing are
digital media hub terminology and
USB drive names.