2.2 Merge and Conflicts

A merge brings changes from one branch into another. A common workflow is: finish work on a feature branch, then merge it back into main.

Basic merge flow

git switch main
git merge feature/search

If Git can automatically combine both sides, the merge completes immediately.

What is a merge conflict?

A merge conflict happens when Git cannot automatically decide what to keep. The most common case is when two branches edit the same area of the same file differently.

A concrete conflict example

Suppose README.md originally contains one line:

Title: Leaflet

On main, you change it to:

Title: Leaflet course home

Your teammate changes the same line on feature/home-title:

Title: Leaflet interactive learning platform

When you run:

git switch main
git merge feature/home-title

Git sees that the same line changed differently on both sides, so it writes conflict markers into the file:

<<<<<<< HEAD
Title: Leaflet course home
=======
Title: Leaflet interactive learning platform
>>>>>>> feature/home-title

Resolving a conflict is not just deleting markers. You decide what the final file should contain. After editing, run:

git add conflicted-file.md
git commit

One reasonable resolution

If both sides contain useful meaning, you can make the final content:

Title: Leaflet interactive course home

Then run:

git add README.md
git commit

This commit means: "The conflict has been resolved by a human, and the merge is complete."