What is an AI agent?
How AI agents differ from chatbots, and how they use tools to take actions.
An AI agent is an LLM-driven system that can plan, call tools and take multi-step actions toward a goal, rather than only replying with text. Agents typically combine a reasoning model, a tool interface (function calling, computer use, browser control) and memory. This guide explains how agents work today, why long-horizon reliability is still hard and how frameworks like OpenAI's Agents SDK and Anthropic's computer use fit in.