Version Control

Version control (also called source control or revision control) is fundamental to modern software development, enabling teams to work together without overwriting each other's changes.

Why it matters

• Enables parallel development through branching and merging.
• Provides complete history of who changed what, when, and why.
• Allows safe experimentation—you can always revert to a working state.
• Essential for code review, CI/CD pipelines, and audit trails.
• Required for compliance in regulated industries (SOX, FDA 21 CFR Part 11).

Types of version control

• Centralized (CVCS): Single server holds the repository (SVN, Perforce).
• Distributed (DVCS): Every developer has full repository copy (Git, Mercurial).

Git fundamentals

• Repository: The database containing all versions and history.
• Commit: A snapshot of changes with a unique identifier (SHA hash).
• Branch: An independent line of development.
• Merge: Combining changes from different branches.
• Pull request: Proposed changes for review before merging.
• Tag: A named reference to a specific commit (usually for releases).

Best practices

• Write clear, descriptive commit messages explaining why changes were made.
• Commit often with small, focused changes.
• Use branches for features, fixes, and experiments.
• Review code before merging to main branch.
• Never commit secrets, credentials, or sensitive data.
• Use .gitignore to exclude build artifacts and dependencies.