gitignore
Domain: Version Control
🎯 Motivation
A .gitignore file tells git which files to skip, keeping secrets, caches, and build artifacts out of your repository. This prevents accidental commits of sensitive data and keeps diffs clean.
📋 Concrete Example
You create a .gitignore containing __pycache__/, .env, and *.pyc so git never tracks Python cache files or your local environment variables.
🔗 Analogy
.gitignore is like a bouncer at a club with a guest list. Files on the list are turned away at the door and never let into the repository.