Git Merge & Git Rebase

Both git rebase and git merge are used to integrate changes from one branch into another. However, they have different approaches and use cases. Let's explore both with an example:

Suppose you have two branches: feature and main, where main is your main development branch, and feature contains a new feature you've been working on.

Here's how you might use both git rebase and git merge in this scenario:

Using git merge:

1. Switch to the main branch:

git checkout main

1. Merge the changes from the feature branch into main:

git merge feature

In this case, the commit history would look something like this:

*   Merge branch 'feature' into main
|\
| * New feature commit 3
| * New feature commit 2
| * New feature commit 1
* | Another main branch commit
* | Main branch commit
|/
* Initial commit

Here, the merge commit records that you merged the feature branch into main.

Using git rebase:

1. Switch to the main branch:

    git checkout main
   

2. Merge the changes from the feature branch into main:

    git merge feature
   

In this case, the commit history would look something like this:

*   Merge branch 'feature' into main
|\
| * New feature commit 3
| * New feature commit 2
| * New feature commit 1
* | Another main branch commit
* | Main branch commit
|/
* Initial commit

Here, the merge commit records that you merged the feature branch into main.

Using git rebase:

1. Switch to the feature branch:

    git checkout feature
   

2. Rebase the feature branch onto main:

    git rebase main
   

In this case, the commit history would look something like this:

* New feature commit 3
* New feature commit 2
* New feature commit 1
* Another main branch commit
* Main branch commit
* Initial commit

Here, the feature branch's commits are applied on top of the latest main branch commit. The history appears linear and cleaner compared to a merge commit.

Key Differences:

• git merge creates a new merge commit that combines changes from different branches. This can make the history more complex.

• git rebase moves the entire history of one branch onto another branch. It creates a linear history, avoiding additional merge commits.

Which to Choose?

Use git merge when you want to maintain a clear record of branch integration and want to capture the fact that a particular feature branch was merged into the main branch. Use git rebase when you want a cleaner and more linear history, often for feature branches or topic branches that you're not sharing with others.

Note: The choice between git merge and git rebase depends on your team's workflow and the desired history structure. Always communicate with your team to decide which approach to use.