Claude Code runs in a terminal. That is fine even if you have never used one; there are two lines to remember.
First you need Node.js: download the LTS build from nodejs.org and follow the installer. It is the same on Windows and Mac.
Then open a terminal - PowerShell from the Start menu on Windows, Terminal via Spotlight on Mac - and type this.
npm install -g @anthropic-ai/claude-code
Do not put sudo in front of that on Mac. It creates permission problems that block later updates; if you hit a permissions error, change how Node is installed instead.
When it finishes, move into your working folder and run claude. The first run walks you through signing in.
cd "C:\\Users\\me\\mymap" # Windows cd ~/mymap # Mac claude
cd means “go to that folder”. Drag a folder from Explorer or Finder onto the terminal window and the path types itself.
Claude Code requires a paid plan, Pro or above.