What is an AI agent

An AI program that does not just answer: it carries out multi-step tasks on its own.

A chatbot answers what you ask. An agent goes further: it receives a goal, decides the steps and uses tools to reach it, such as reading email, searching the web, filling in a spreadsheet or sending a message.

That is why it is useful and why it needs limits. The usual approach is to give it only the access it needs and to ask for a person's approval before any sensitive action.