Version Control (Git)
What Is Version Control?
Version control is the practice of tracking, managing, and preserving changes to files over time so that specific versions can be retrieved, compared, and restored at any point in the project’s history. In software development, version control systems record every change made to source code, along with who made it, when, and why, creating a complete, auditable history of the project’s evolution.
Git is the most widely adopted version control system in the world. It is a distributed version control system, meaning every developer working on a project has a full copy of the repository on their local machine, including the entire change of history. This architecture enables teams to work independently without a constant connection to a central server, while still providing mechanisms to coordinate and integrate their work.
How Git Works
Repositories
A Git repository (repo) is the directory that contains the project files along with the metadata Git uses to track the full change history. Repositories can be local, residing only on a developer’s machine, or remote, hosted on platforms such as GitHub, GitLab, or Bitbucket where team members can access, push, and pull changes.
Commits
A commit is a recorded snapshot of the repository at a specific point in time. Each commit captures what changed, attaches the author’s identity and timestamp, and includes a message describing the change’s purpose. Commits are the fundamental unit of Git history: every change is preserved as a commit, and the full project history is the ordered sequence of all commits.
Branches
Branching allows developers to create independent lines of development from any point in the repository history. A developer working on a new feature creates a branch, makes changes to that branch without affecting the main codebase, and merges the branch back when the work is complete and reviewed. Branches enable parallel development across multiple features without mutual interference.
Merging and Pull Requests
When work on a branch is complete, it is merged back into the main branch. In collaborative team environments, this merge happens through a pull request (or merge request), where the developer requests that their changes be reviewed by peers before integration. Code review through pull requests catches errors, enforces standards, and spreads knowledge across the team before changes reach the shared codebase.
Remote Collaboration
Remote repositories enable distributed teams to collaborate on shared codebases. Developers push their committed changes to the remote repository and pull the latest changes from it to stay synchronized. Git’s merge mechanisms handle cases where multiple developers have modified the same files, identifying conflicts that require human resolution.
Git in CI/CD and DevOps
Git repositories serve as the source of truth that drives continuous integration and continuous delivery of pipelines. Commits to specific branches trigger automated build, test, and deployment workflows, translating code changes into tested, deployable artifacts with minimal manual intervention. Git’s branching model is the operational foundation of most modern CI/CD architectures.
Git Hosting Platforms
- GitHub: The most widely used Git hosting platform, offering repository hosting, code review workflows, project management, and CI/CD through GitHub Actions.
- GitLab: A comprehensive DevOps platform built around Git, including integrated CI/CD, issue tracking, container registry, and security scanning.
- Bitbucket: Atlassian's Git hosting platform, tightly integrated with Jira for project management and Confluence for documentation.
Key Takeaways
- Version control tracks and preserves every change made to a project's files over time, enabling retrieval, comparison, and rollback to any historical state.
- Git is a distributed version control system where every developer holds a complete copy of the repository and its full history.
- Core Git concepts include repositories, commits, branches, merging, and pull requests, each serving a specific role in collaborative development workflows.
- Pull requests combine code integration with peer review, catching errors and enforcing standards before changes reach the shared main codebase.
- Git repositories are the source of truth for CI/CD pipelines in DevOps environments, with commits triggering automated build, test, and deployment workflows.