2.2Merge

A merge creates a new "merge commit" that combines the histories of two branches. The full branch history is preserved in the graph.

git checkout main
git merge feature/login-tests
# Creates a merge commit; feature branch history visible in graph

What the history looks like after merge:

main:    A --- B --- C --- M (merge commit)
                    /     /
feature: D --- E --/

Both the main branch commits (A, B, C) and the feature branch commits (D, E) are visible. The merge commit (M) marks where integration happened.

Advantages of Merge

• Preserves history: You can see exactly when a feature branch was created and merged
• Safe for shared branches: Never rewrites existing commits
• Easy to revert: Revert the merge commit to undo an entire feature

Disadvantages of Merge

• Cluttered history: Many merge commits can make the log hard to read
• Noisy diffs: Merge commits can make git log --oneline harder to scan