Git is a distributed version control system that allows software engineers to track changes in source code during software development. It is designed to handle everything from small to very large projects with speed and efficiency. This glossary entry will provide a comprehensive understanding of Git, its history, use cases, and specific examples.
Git was created by Linus Torvalds in 2005 for the development of the Linux kernel, with other kernel developers contributing to its initial development. It is free and open source software distributed under the terms of the GNU General Public License version 2. Git's current functionality is implemented in software that is independent of the underlying version control system.
Definition of Git
Git is a distributed version control system that enables multiple people to work on a project at the same time without overwriting each other's changes. It allows developers to create branches to experiment with versions of a project. Git ensures that the master branch always contains production-quality code.
Git is designed to handle large projects that require speed and efficiency. It is a tool that is used by software developers for version control of their projects which allows them to track changes, revert to previous stages, and collaborate with their team in the same codebase.
Key Features of Git
Git has several key features that set it apart from other version control systems. These include its distributed nature, its speed, and its data integrity capabilities. Git allows each developer to have their own local repository, complete with a full history of commits. This means that if any server dies, the data can be restored from any of the client repositories.
Git is also incredibly fast, as most operations are performed locally, eliminating the need for a network connection. Git's data integrity capabilities are top-notch, as it uses a cryptographic algorithm called SHA1 to name and identify objects within its database.
Git Terminology
Understanding Git requires familiarizing oneself with some specific terminology. 'Repository' or 'repo' refers to a directory where Git has been initialized to start version controlling your files. 'Commit' is a snapshot of your work at a point in time. 'Branch' is a parallel version of a repository. It is contained within the repository, but does not affect the primary or master branch allowing you to work freely without disrupting the live version. When you've made the changes you want to make, you can merge your branch back into the master branch to publish your changes.
'Forking' a repo refers to creating a new project based off of another project that already exists. 'Cloning' a repo creates a copy of the repo in a new directory, on your local machine. 'Pull' refers to fetching in changes and merging them. 'Push' refers to sending your committed changes to a remote repository on GitHub, for example.
History of Git
Git was created by Linus Torvalds in 2005. Torvalds, the creator of the Linux operating system, developed Git after a falling out with the team responsible for BitKeeper, a proprietary distributed version control system that was previously used by the Linux team. Despite the initial resistance to Git's cryptic command line interface, it quickly gained adoption within the Linux community.
Git's design was inspired by BitKeeper and Monotone. Git was originally designed as a low-level version control system engine, on top of which others could write front ends, such as Cogito or StGit. However, Git has since become a full-fledged, fully-featured version control system that can be used directly.
Git's Impact on Software Development
Git has had a significant impact on software development practices by introducing features that support both non-linear development and distributed collaboration. These features have helped to promote decentralized workflows, encouraging developers to work in their own branches, isolate their work, and experiment with new ideas in a safe environment, before sharing their changes with others.
Git's impact extends beyond just software development, as it has also been used to version control books, dissertations, and other non-code writing. It has also been used in academia to teach students about version control practices.
Use Cases of Git
Git is used in both commercial and open-source software development environments. Its distributed nature makes it an ideal tool for collaborative projects, allowing teams to work on the same codebase without the risk of overwriting each other's changes. It also allows developers to work offline, as they can commit changes to their local repository before pushing changes to the central repository.
Git is also used in other non-development fields to manage different versions of digital assets, such as documents, designs, and other types of content. Its ability to handle large amounts of data and its fast performance make it an ideal tool for version control in various contexts.
Git in Software Development
In software development, Git is used as a distributed version control system that enables developers to work on a project simultaneously. Git is used to track changes in the source code, allowing developers to revert back to a previous state, compare changes over time, and ensure that changes made by multiple developers do not conflict with each other.
Git's branching feature allows developers to create separate branches to develop new features or fix bugs, without affecting the main project. This feature also allows developers to experiment with new ideas in a safe environment, without the risk of affecting the main project.
Git in Other Fields
Outside of software development, Git is also used in various fields to manage different versions of digital assets. For example, in graphic design, Git can be used to version control different versions of a design. This allows designers to experiment with different ideas, revert back to a previous version, and even collaborate with other designers in a distributed manner.
In academia, Git is used to version control research papers, theses, and other written works. This allows authors to track changes over time, revert back to a previous state, and collaborate with other authors in a distributed manner. Git is also used in education to teach students about version control practices.
Specific Examples of Git Usage
One of the most common use cases of Git is in open source projects, where it allows developers from around the world to collaborate on a project. One such example is the Linux kernel, which is developed by a distributed team of developers. Each developer works on their own branch, makes commits to their local repository, and then pushes their changes to the central repository.
Another example of Git usage is in commercial software development. Many companies use Git as their version control system because of its distributed nature and its ability to handle large codebases. For example, Microsoft uses Git to manage the Windows codebase, which is over 300 GB in size and includes over 3.5 million files.
Git in Open Source Projects
Git is widely used in open source projects. One of the most notable examples is the Linux kernel, which is developed by a distributed team of developers. Each developer works on their own branch, makes commits to their local repository, and then pushes their changes to the central repository. This allows the team to work on the project simultaneously, without the risk of overwriting each other's changes.
Another notable open source project that uses Git is the Ruby on Rails web framework. The Rails team uses Git to manage their codebase, track changes, and collaborate with contributors from around the world. This has allowed the Rails project to grow and evolve over time, with contributions from thousands of developers.
Git in Commercial Software Development
Many commercial software development companies use Git as their version control system. For example, Microsoft uses Git to manage the Windows codebase. The Windows codebase is over 300 GB in size and includes over 3.5 million files. Despite its size, Git is able to handle the Windows codebase efficiently, thanks to its distributed nature and its ability to handle large amounts of data.
Another example is Google, which uses a custom version of Git called "Repo" to manage the Android codebase. Repo is a tool that makes it easier to work with Git in the context of large codebases, such as the Android operating system. Despite the custom tooling, the underlying version control system is still Git.
Conclusion
Git is a powerful tool that has revolutionized the way developers work. Its distributed nature, its speed, and its data integrity capabilities have made it the go-to version control system for many software development projects, both open source and commercial.
Whether you're a developer working on a large codebase, a designer experimenting with different designs, or a writer working on a book, Git can help you manage your work, track changes, and collaborate with others in a distributed manner. Understanding how Git works and how to use it effectively can greatly improve your productivity and the quality of your work.