An LLM only knows what it saw in training. It doesn't know your company wiki, last week's news, or the PDF you just uploaded. Ask it anyway and it either refuses or — worse — confidently makes something up.
RAG (Retrieval-Augmented Generation) fixes that, and it's far simpler than the name suggests. This is Day 5 of my PromptFromZero series.
RAG in one sentence
Fetch the relevant facts at question time, and hand them to the model to read.
You're not asking the model to remember. You're giving it the page to read.
