Everything you need to understand AI coding assistants — from the model underneath to the agents on top.

This documentation follows the AICA Onion — a six-layer model that explains how AI coding assistants work from the ground up. Start with the concepts if you’re new, or jump to the GitHub Copilot section if you want Copilot-specific guidance. The glossary is always at the bottom when you need a quick definition.

Concepts

PageWhat it covers
What is a Model?The AI engine underneath every coding assistant
What is an AI Coding Assistant?The product that wraps the model
What is an Agent?Autonomous task executors — and why Copilot has two kinds
Models vs AgentsThe core comparison — what’s different and why it matters
What is MCP?The protocol that connects agents to tools
Skills & ToolsWhat agents can actually DO

Guides

Practical walkthroughs for real scenarios. (Coming soon)

Glossary

Full Glossary — Plain-English definitions for every term on this site

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