When you work on a project, you and your teammates might each try out new ideas in your own branches. At some point, you will want to combine these ideas so everyone benefits. Merging is how you bring the work from different branches together. You can think of merging like solving a puzzle: each branch is a piece, and merging fits those pieces together to make a complete picture. This lets you safely experiment and then combine your progress without losing anyone’s work.

# Make sure you are on the branch you want to merge INTO, usually 'main'
git checkout main

# Merge changes from the 'new-idea' branch into 'main'
git merge new-idea

Here’s what happens step-by-step during a merge:

1. You start on the branch you want to bring changes into, usually main;
2. You run the git merge command with the name of the branch that has the changes you want;
3. Git looks at both branches, finds the new work, and tries to combine it;
4. If there are no conflicting changes, Git adds the new commits to your current branch;
5. The result is a branch with all the combined changes, just like finishing a puzzle with all the pieces in place.

Merging is useful because it lets you keep your main project up to date with everyone’s improvements, while still letting people try out new ideas in separate branches.

# You are on 'main' branch, and 'new-idea' has new changes
git merge new-idea

# Output when there are no conflicts:
Updating 3e1b2c1..7f4d2e9
Fast-forward
 new-feature.txt | 1 +
 1 file changed, 1 insertion(+)