02
Tokens, cost and your first RAG
What a model reads and pays for, and the whole RAG lifecycle in miniature.
Concept 2.1
Tokens and context windows for RAG
What a token is, why every limit and price in RAG is counted in tokens, and how to budget a prompt so the answer still fits.
Concept 2.2
The RAG lifecycle and your first RAG in miniature
The two halves of every RAG system, building the index and answering a question, shown end to end on a small corpus you can run in the browser.
Chapter 2 recap