Agent
What it is
What it is
Written by Martin Ågren - February 21, 2026
Many people talk about "AI agents" nowadays, but what is it? And are people referring to the same thing?
When people use the word "agent" they can sometimes refer to different types of AI systems e.g. different levels of autonomy (or multi-agent systems (MAS) or single agent only).
In the classic book "Artificial intelligence: a modern approach" (by Stuart Russell & Peter Norvig, 4th edition - written 2020 before the release of ChatGPT) agents are defined like this (shortened version):
An agent is perceiving its environment through sensors and acting upon that environment.
Clarifications:
Sensors = Receive input from the environment.
An agent’s environment can be physical or digital. However, a physical environment needs to be digitized to be usable as an environment.
Nowadays, when people use the word "agent", they are often referring to an trained, LLM powered agent with high level of autonomy. That is when the AI agent can work step-by-step (more or less autonomously) towards your defined main goal, based on your input prompt.
Another form of solution, is an AI automation. Sometimes when people say "agent", they could be referring to an AI automation.
An AI automation is a rule-based (traditional) workflow (nodes/steps following fixed rules) that includes ML-based data processing.
ML = A sub-field of AI where systems learn patterns from data to make predictions or decisions without being explicitly programmed for each task.
Automation process without AI:
Note that an automation workflow does not necessarily need to incorporate AI. If the automation process does not include AI, it is just an "automation process", not an "AI automation".
Created by AI:
An interesting twist, though, is that such automation (without AI) could be created with help from AI.
Sometimes when people say to me that they have "created an AI agent" I find that they in fact has customized an AI chatbot.
Example of a customized version of an AI chatbot is:
Custom GPT or Project assistant inside of ChatGPT.
"Assistant" could mean a lot of things. It could mean a customized version of an AI chatbot, or it could mean an autonomous AI agent, or it could mean something else.