How It Works
Application layer
The part of an AI product people actually touch — the app, chatbot or feature — built on top of someone else's AI model. A company like a legal-document assistant sits in the application layer; the model underneath (GPT, Claude and so on) is the 'foundation layer'.
Origin · no single documented coiner
Borrowed from older networking and software terminology, where the 'application layer' is the top of the stack. In AI it spread through investor and startup writing from about 2023 as a way to sort companies into model-makers versus app-builders. No single documented coiner for the AI usage.
No single primary source link for this term.