Repositories, commonly referred to as “repos,” are the cornerstone of GitHub. They serve as centralized storage for your project’s code, documentation, and associated files.

GitHub is a platform over 100 million developers use to build software. It's a subsidiary of Microsoft, and has both free and paid versions.

GitHub is at heart a Git repository hosting service, i.e. a cloud-based source code management or version control system, but that’s just the beginning.