# Fundamentals

## Pages

- [Tokens: The Unit AI Thinks (and Bills) In](https://www.fernandoux.com/en/wiki/ai/tokens/)
  A token is the chunk of text an AI model processes as one unit. What tokens are, how many a word has, how they are counted and how they affect cost and limits.
- [What Is an AI Agent?](https://www.fernandoux.com/en/wiki/ai/what-is-an-ai-agent/)
  An AI agent decides its own steps, uses tools to act and reviews the results until it finishes. How it works and how it differs from a chatbot or a workflow.
- [What Is an LLM? Explained for Designers](https://www.fernandoux.com/en/wiki/ai/what-is-an-llm/)
  An LLM is a language model trained on huge amounts of text to predict the next token. Here is how it works and what it means for the people who design with it.


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Source: https://www.fernandoux.com/tags/fundamentals/