Version control is a system that records changes to files over time, allowing developers to track modifications, revert to earlier states, and collaborate on code without overwriting each other's work. It is one of the foundational practices in modern software development, and understanding it is essential for anyone working on a codebase of any meaningful size.
At its core, version control works by maintaining a complete history of every change made to a project. Each time a developer saves a meaningful set of changes, they create what is called a commit - a snapshot of the project at that moment in time. These commits are stored in a repository (also called a repo), which can live locally on a developer's machine, on a remote server, or both. This history makes it possible to understand not just what changed, but when it changed and, with good commit messages, why it changed.
There are two broad categories of version control systems. Centralized version control systems, such as Subversion (SVN), rely on a single central server that holds the authoritative history of the project. Developers check out files from this server and commit changes back to it. Distributed version control systems, such as Git, take a different approach: every developer has a full copy of the repository, including its entire history. This makes distributed systems more resilient and better suited to the decentralized workflows common in open-source and remote development.
Version control also enables branching, which allows developers to diverge from the main line of development to work on a feature or fix in isolation. Once the work is complete, the branch can be merged back into the main codebase. This workflow prevents unstable or incomplete code from disrupting the work of others on the same project.
For teams, version control is what makes parallel collaboration possible. Without it, multiple people editing the same file would risk silently overwriting each other's changes. Version control systems detect these conflicts and prompt developers to resolve them deliberately, preserving the integrity of the codebase.
Beyond development teams, version control has relevance for web professionals more broadly. Content configurations, deployment scripts, and even SEO-related files such as robots.txt or redirect maps are increasingly stored in version-controlled repositories, giving non-developers a clearer audit trail and the ability to roll back unintended changes. Platforms like GitHub and GitLab have built collaboration and project management tools directly on top of version control, making it a central hub for modern web projects.