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intermediate7 bits • 27 min total

Code Fundamentals

Essential concepts every developer should know. From version control to data formats, these bits build the foundation for understanding modern software.

Learning Path

What Is a Hash?

Hashes are everywhere: passwords, git commits, blockchain. They're like fingerprints for data.

Git Commit Hashes at a Glance

Every git commit has a hash like '3f7a2b1'. It's not random — it's a cryptographic snapshot.

Git Branch vs. Commit

Branches and commits are both fundamental to git — but they're not the same thing. Here's the difference.

Environment Variables Explained

API keys, database URLs, secrets — where do they live in production? Not in your code.

What Is an API?

APIs power every app you use. They're how software talks to other software — here's the plain-language version.

JSON is everywhere on the web. It's the language APIs speak — and it's simpler than it looks.

What Does Open Source Mean?

Linux, React, VS Code — all free and open source. But 'open source' isn't just about price.