Vector Databases Explained: What They Don’t Tell You

Everyone working in AI reaches a moment where they search a document and get back something that looks right but means nothing — or searches for a concept and gets back noise. That moment is when they discover vector databases. This guide covers everything: the math, the architecture, the algorithms, the top tools, and — most importantly — what vector search alone cannot do for an AI agent that needs to remember. What is a vector? Embeddings from first principles A vector is just a list of numbe