Imagine you're writing an important paper. You finish a draft and save it as Essay_v1.docx. Then you make some big changes and save it again as Essay_v2.docx. A few hours later, you have Essay_final.docx, followed by the inevitable Essay_REALLY_final.docx.

This system is messy and confusing. If you want to go back to an idea from your first draft, you have to hunt through old files. If you're working with a partner, you end up emailing files back and forth, trying to merge your changes without overwriting each other's work. It’s a recipe for disaster.

Version Control Systems (VCS) solve this problem. A VCS is like a time machine for your project. It’s a system that records changes to a file or set of files over time so that you can recall specific versions later. Instead of saving multiple copies of a file, you save “snapshots” of your work at different points. This lets you track your project's history, see who changed what, and revert to older versions if something breaks.

Version control systems generally come in two types: centralized and distributed.

Centralized Version Control Systems (CVCS) use a single, central server to store all the files and their history. To work on the project, you “check out” the files from that central server. It’s like a library: there’s one main copy of a book, and you check it out to read it. The major downside is that if the central server goes down, nobody can collaborate or save their changes.

Distributed Version Control Systems (DVCS) are different. Instead of just checking out the latest version of the files, you get a full copy of the entire project history. Every developer has a complete backup of the repository on their own machine. This makes collaboration more flexible and robust. If the main server is offline, you can still work, save your changes locally, and even share changes with other developers directly.

The most popular distributed version control system in the world today is Git. It's fast, efficient, and excellent at managing projects of any size. Because it's distributed, every developer has the full history of the project, which makes it easy to work offline and merge changes later.

So, if Git is the tool that tracks changes, what is GitHub?

GitHub is a platform that hosts Git repositories in the cloud. Think of it as a social network for developers. It provides a web-based home for your projects, making it easy to store your code, collaborate with others, and manage your work. GitHub adds a user-friendly interface on top of Git's powerful command-line tools.

With GitHub, you can:

• Store your Git repositories online so you have a backup.
• Share your code with others and browse open-source projects.
• Collaborate with team members through features like pull requests and code reviews.
• Track issues, bugs, and feature requests for your project.

Together, Git and GitHub form the backbone of modern software development. Git handles the version control on your local machine, while GitHub provides the platform for collaboration and sharing.

Now that you have a high-level understanding of what version control is, you're ready to see how it works in practice.