What is the difference between Git merge and Git rebase?

Both combine branches but in different ways:

**Git Merge:**
- Creates a new merge commit
- Preserves complete history with all branches visible
- Non-destructive operation
- History looks like: A—B—C—M (M is merge commit)

```bash
git checkout main
git merge feature-branch
```

**Git Rebase:**
- Re-applies commits from one branch onto another
- Creates linear history (cleaner log)
- Rewrites commit history
- History looks like: A—B—C—D—E (straight line)

```bash
git checkout feature-branch
git rebase main
```

**When to use:**
- Merge: for integrating completed features (preserves context)
- Rebase: for keeping feature branch up-to-date with main (cleaner history)

**Golden rule:** Never rebase shared/public branches — it rewrites history and breaks others' work.