AI Agent
An AI agent is defined less by the model behind it than by whether it can plan steps, call tools and finish a task on its own.
To tell an AI agent from a chatbot, ask three things: does it break the goal into steps, does it change course mid-run, and can it call external tools. A chatbot stops once the answer is out, a workflow follows the diagram you drew, while an agent decides the next move during execution. The more open-ended and variable-rich the task, the more it is worth; stable processes with a high cost of error are still better served by a plain workflow.