Knowledge Base
A knowledge base is a collection of documents kept as the reference answer to a set of questions. For a business it is the help articles and policies its customers and staff look things up in; for an AI system it is the body of text the system retrieves from before it writes an answer.
Two meanings, one shape
The support knowledge base is organized by question: one article per thing people ask, with a title that is the question and a body that answers it. The retrieval knowledge base behind a retrieval-augmented system is organized the same way at a finer grain: documents are cut into passages, each passage is stored with a representation of its meaning, and at answer time the passages closest to the question are pulled out and handed to the model. In both, a document earns its place by being findable from the question and complete once found.
Your website as somebody else’s knowledge base
When an assistant fetches a page on a buyer’s behalf, that page is the knowledge base for that answer. The passage it lifts has to answer the question in one place and say who is speaking. This site’s audit of 9,483 small-business sites recorded how many carried question-and-answer content of any kind, and how many had a heading phrased as a question with no answer isolated beneath it; the counts are in what 9,483 small business websites serve to an AI crawler. A homepage of several hundred words that never answers a question is, to a retrieval system, an empty knowledge base.
Knowledge base and knowledge graph
A knowledge base stores text and retrieves passages. A knowledge graph stores entities and the relationships between them, and answers by traversal rather than retrieval. The two are often used together, and the terms are confused because both hold what a system knows.
A common question
Can a homepage count as a knowledge base for an AI assistant?
Only if it answers something. When an assistant fetches a page to settle a buyer's question, that page acts as the reference text for that one answer, so it has to carry a passage that resolves the question on the spot and makes clear who is speaking. A homepage of several hundred words that never answers anything gives a retrieval system nothing to pull, which leaves it empty in the only sense that matters here.