When a shopper asks an assistant "what's the best automatic litter box under $400," the answer is assembled from two very different sources. The first is training data — the text the model learned from, which is months to years old and encodes brand-level knowledge: which names are established and roughly what they are known for. The second is live retrieval — a real-time search step that fetches current pages and quotes or summarizes them.
The split matters because the two are influenced on completely different timescales. Training data is effectively frozen; a new pet supplies brand cannot appear in it until models are retrained on a web that already talks about the brand. Retrieval, by contrast, updates as fast as the underlying index — a page published this month can be fetched and cited this month.
Every practical lever in this article targets retrieval, because that is the layer a merchant can move this quarter. Training-data presence follows later, as a byproduct of the same third-party coverage that helps retrieval today.