GitHub

Think of GitHub as Google Docs for code. When you write a document in Google Docs, it's saved online, you can share it with others, track changes, and go back to previous versions. GitHub does the same thing for code.

Every software project you've ever heard of — from the code behind websites to operating systems to AI models — probably lives on GitHub. It's where developers store their code, track every change they make, collaborate with other developers, and share their work with the world.

The "Git" part is the version control system that tracks changes (like "Track Changes" in Word, but way more powerful). The "Hub" part is the social platform where millions of developers share and discover code. Together, it's the center of the software universe.

Because if you start building anything with code — even with vibe coding tools — you'll end up on GitHub sooner or later. It's where you'll store your projects, deploy your websites (many hosting services connect directly to GitHub), and find other people's code to learn from. Having a GitHub account is basically a prerequisite for building in tech.

GitHub hosts Git repositories with additional features: pull requests for code review, Issues for bug tracking, Actions for CI/CD, Packages for artifact hosting, Codespaces for cloud development environments, and Copilot for AI code assistance. It hosts 200M+ repositories and 100M+ developers. Alternatives include GitLab (self-hostable) and Bitbucket. Acquired by Microsoft in 2018 for $7.5B.