The AICA Onion is a 6-layer mental model that maps the full stack — from raw AI model at the centre, out to the assistant you use daily, the agents it runs, the orchestrator layer, and the instruction files and tools that extend it all — so the same word never trips you up twice. Start with the onion — everything else will make sense from there.
Models
The AI brains behind the answers. Learn what a model actually is, how different models compare, and how to choose the right one for your workflow.
Agents
More than autocomplete. Agents take actions, use tools, and work autonomously. Understand how Copilot agents differ from the models that power them.
Skills, MCP & Extensions
How agents get superpowers. Skills, MCP servers, and extensions are how you extend what an agent can do — and they’re not the same thing.