Fast-Forward & 3-Way Merge
git merge yourBranch
Fast-Forward merge
When the master branch has no new commits, Git simply moves the master pointer forward to the latest feature commit without creating a new merge commit.
3-way merge
When both branches have evolved independently, Git combines their histories by generating a brand new “merge commit.”
Squash Merge
Git condenses all feature branch commits into a single new commit on the master branch, keeping the main repository history completely linear.