1) It stores a history of important changes
2) It enables collaborative work on a project.
Git is essentially a (free) program that you install on your computer. It was invented by Linus Torvalds when he created Linux (but now it also runs on Windows and Mac). You can connect Git to your IDE (for example, VS Code), grant it access to your project folder and it will start tracking all changes in that folder (which you can now call a "Repository"). But the point isn't to create a huge list of small edits.
Typically, during development, you plan tasks to implement features. When you complete a task, you can add a so-called "Сommit" to Git - like a checkpoint in a game. So, Git maintains a history of these Commits and you can revert changes to any of them. This is useful if you've deployed a program to production and then a bad bug was discovered. You can also see a list of all the minor changes since the previous commit, giving you the opportunity to start working on a new feature from scratch.
But Git's main function is to coordinate collaborative program development. Without it, developers would have to send code back and forth, endlessly negotiating what can and can't be changed until someone finishes the new feature.
Git makes it very easy to create copies (branches) of a project. Typically, "main" branch is created with the production code and "dev" branch with the new version. When a developer wants to develop a new feature, a "feature" branch is created for them, which also contains the entire project code. By switching to this branch on their computer, the developer can finish the feature and test it in the program without disturbing others. When the feature is ready, they make a "Pull request", asking the project maintainer to accept the changes. The maintainer reviews it and if everything is OK, merges the feature-branch into the dev-branch. And when all the new features are ready, they can merge the dev-branch into the main-branch and push out the release.
Git used to work as a p2p system before, but then GitHub appeared - a cloud service that allows you to store a project's main repository. It's mostly free (though owned by Microsoft), so most projects use it.
Here are some free PDF books about Git:
GitHub For Dummies
2019 by Sarah Guthals, Phil Haack
Download PDF
Version Control with Git: Powerful tools and techniques for collaborative software development
2009 by Jon Loeliger
Download PDF
GitHub Actions in Action: Continuous integration and delivery for DevOps
2025 by Michael Kaufmann
Download PDF
See also: Top 10 eBook Organizers
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