What Is RAG (Retrieval-Augmented Generation)? How AI Looks Things Up Before Answering
When an AI assistant answers using your company's internal documents, or cites this morning's news, the machinery behind it is almost always RAG — Retrieval-Augmented Generation . The term shows up in every enterprise AI pitch, but the idea itself is refreshingly simple. Here is how RAG works, what problems it actually solves, and where it still falls short — no math required. RAG in one sentence: the AI looks things up first A plain language model answers from whatever it memorized during training — a closed-book exam . RAG turns it into an open-book exam : for every question, the system first searches a collection of documents, pulls the relevant passages, and lets the model read them while writing its answer. Retrieval — find documents related to the question Augmented — insert those documents into the model's prompt Generation — write the answer grounded in that material The three problems RAG solves Stale knowledge. Models have a training cutoff and know nothing af...