Git is a popular version control system used by software developers to manage changes to their code. One of the most common tasks in Git is to merge changes from one branch into another. However, Git offers two different approaches to do this: merge and rebase. Both merge and rebase have their pros and cons, and understanding the differences between them is crucial for developers to make informed decisions.

In this article, we will discuss the differences between Git merge and Git rebase, how they work, and when to use each of them.

Git Merge

Git merge is a command that combines changes from two or more branches into a single branch. The merge creates a new commit that incorporates the changes from the source branch into the destination branch.

To perform a merge, you need to check out the branch that you want to merge changes into and then run the git merge command followed by the name of the source branch. For example, to merge changes from a branch named "feature-branch" into the current branch, you can use the following command:

git checkout main
git merge feature-branch

Git merge creates a new merge commit that has two parent commits: one from the current branch and another from the source branch. This merge commit represents the point where the two branches were merged, and it contains all the changes from both branches.

One advantage of Git merge is that it preserves the commit history of both branches. Developers can easily see which commits were made on which branch and when they were merged. Moreover, Git merge is a safe option when working with shared repositories because it does not alter the commit history.

However, Git merge can create clutter in the commit history by creating many merge commits, especially when merging frequently or with a long-running branch. This can make it harder to track changes in the codebase and can result in merge conflicts that need to be resolved manually.

Git Rebase

Git rebase is a command that integrates changes from one branch into another by moving the entire branch to a new base commit. This means that Git rebase replays the changes made in the source branch on top of the destination branch, creating a linear history of commits.

To perform a rebase, you need to check out the branch that you want to rebase and then run the git rebase command followed by the name of the source branch. For example, to rebase changes from a branch named "feature-branch" into the current branch, you can use the following command:

git checkout main
git rebase feature-branch

Git rebase applies the changes made in the source branch on top of the destination branch, creating a new commit for each change. This results in a linear history of commits, where each commit builds on the previous one.

One advantage of Git rebase is that it creates a clean commit history that is easy to follow. Developers can see the changes made in the source branch as a series of commits on top of the destination branch, without clutter from merge commits. Moreover, Git rebase can help to reduce the number of merge conflicts because it replays the changes on top of the destination branch.

However, Git rebase can be risky when working with shared repositories because it alters the commit history. When you rebase a branch, you create new commits that replace the old ones. This means that if someone else has already based their work on the old commits, they will need to rebase their work on top of the new commits. This can create conflicts that need to be resolved manually.