An AI agent is an autonomous software system that uses a reasoning engine (typically a Large Language Model) to perceive its environment, reason about goals, and execute multi-step actions using external tools to achieve a specific objective. It basically uses an LLM as its brain.
Unlike standard LLMs, which are reactive (answering prompts), agents are proactive (pursuing goals). Some example differences between them:
- capabilities: the standard LLM can generate text and code, and the AI agent can get to action execution via APIs/Tools
- logic: the LLM works with one-shot generation while the AI agent can do iterative planning and correction
- memory: a standard LLM resets at every session while the AI agent’s memory persist via external storage
The agentic loop identifies the core components of AI agents.