Git Branching and Merging — Branches, Merge, Conflicts and Rebase

A branch is a separate line of work. You build a feature on its own branch while main stays stable; when it's ready, you merge it back.

1. Branch commands

git branch                       # list branches (* = current)
git switch -c feature/login      # create AND switch to a new branch
# ... edit, add, commit ...
git switch main                  # go back to main
git merge feature/login          # bring the feature into main
git branch -d feature/login      # delete the merged branch

(Older tutorials use git checkout -b — same idea.)

A branch is just a lightweight pointer to a commit, so creating one is instant.

2. Fast-forward vs merge commit

• If main hasn't changed since you branched, Git just moves main forward — a fast-forward.
• If both changed, Git creates a merge commit with two parents.

3. Merge conflicts

A conflict happens when both branches changed the same lines. Git can't guess which is right, so it asks you.

How to resolve:

1. git status lists the conflicted files.
2. Open each file; find the <<<<<<<, =======, >>>>>>> markers.
3. Edit to the correct final code (keep one side, the other, or combine) and delete the markers.
4. git add file → git commit.

VS Code shows buttons: Accept Current, Accept Incoming, Accept Both.

Pull often and keep branches short-lived — small, frequent merges mean small, easy conflicts.

4. merge vs rebase

git switch feature/login
git rebase main          # replay my commits on top of the latest main

Golden rule: never rebase commits that others have already pulled. Rebase only your own local branch.

5. Branch naming

Teams usually use prefixes: feature/payment-upi, fix/login-crash, docs/readme, chore/upgrade-deps.

Common mistakes

• Working directly on main for everything.
• Leaving conflict markers in code and committing.
• Rebasing a branch your teammates also use.

Quick recap

• git switch -c name → work → git switch main → git merge name.
• Fast-forward when main hasn't moved; otherwise a merge commit.
• Conflicts: edit, remove markers, add, commit.
• Merge = safe true history; rebase = clean line, only on your own branches.