Understanding Git Branches and PRs: Why do we create a new branch, and what happens upon merging?

[Himanshu-5680]

I have a fundamental doubt:

• ​Why is it strictly recommended to create a new branch when working on an issue instead of committing directly to the main branch?

• ​Once my Pull Request (PR) is approved and merged into the main repository, what exactly happens to my feature branch and its commits?

[wanjikubrians-khim]

Why Avoid Committing Directly to Main
• Code Isolation: It keeps the main branch stable and production-ready at all times. Your branch serves as a safe sandbox where breaking things won't affect teammates.
• Code Review: It allows automated tests and peers to review your changes via a Pull Request. You cannot safely test or peer-review code that is already pushed live.
• Parallel Work: It lets multiple developers work on different features at the exact same time. Without branches, overlapping incomplete code would constantly break the project.

What Happens After the PR Merges
• Your Commits: They are either preserved entirely, compressed into one single commit, or replayed linearly onto main. This depends entirely on the specific merge strategy your team chooses.
• Remote Branch: The branch on GitHub or GitLab is safely deleted to keep the repository clean. Most hosting platforms handle this automatically right after the merge.
• Local Branch: The branch stays on your personal computer until you manually delete it. Git will never delete local files unless you run the cleanup command.

[Meyyappan-AL]

Why not commit directly to main?

It keeps the main app safe: Main is like the final, working product. Working on a separate branch lets you test new ideas without breaking the app for users or teammates.
It allows for code reviews: Creating a separate branch lets you open a Pull Request (PR) so teammates can check your code for bugs or errors before it gets added to the main project.
It makes teamwork easier: Multiple developers can work on different features at the same time on their own branches without accidentally deleting or overwriting each other's work.

What happens after a Pull Request (PR) is merged?

Your changes (commits): Your work gets copied over and combined into the main branch so everyone can see and use your new feature.
The branch on GitHub: The branch on GitHub is usually deleted right after merging to keep the project clean and organized.
The branch on your computer: The branch remains on your laptop or computer until you delete it yourself using the terminal

command: git branch -d branch-name.