What is Claude Code and why it matters

Claude Code is Anthropic's official command-line AI that runs as a peer engineer alongside your terminal. It reads your files, writes code, runs tests, commits to git, and reasons across your entire codebase — not just the line your cursor is on.

What makes it categorically different

• ▸Full filesystem access — reads, writes, moves files natively without copy-paste
• ▸Tool use — runs bash commands, git operations, and calls external APIs
• ▸Persistent session context — remembers everything you've said and shown it
• ▸Extensible — hooks, skills, and MCP servers let you wire in any tool or workflow

The paradigm shift

Traditional AI tools are autocomplete engines. You think of the implementation, they fill in syntax. Claude Code inverts this: you describe the outcome you want, and it figures out what to read, what to change, and in what order — across however many files that takes.

The best Claude Code users don't write code. They review code. They describe outcomes, Claude proposes implementations, and engineers apply judgment to the diff. This is the workflow this course teaches.

Watch it work — live demo

Click the terminal below to see Claude Code build a real feature from a single prompt. Every tool call is real — it reads your files, figures out the architecture, and writes the code: