What s the difference between git merge and git rebase

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User · Answer

Personally I don t find the standard diagramming technique very helpful - the arrows always seem to point the wrong way for me   They generally point towards the  parent  of each commit  which ends up being backwards in time  which is weird    To explain it in words    When you rebase your branch onto their branch  you tell Git to make it look as though you checked out their branch cleanly  then did all your work starting from there  That makes a clean  conceptually simple package of changes that someone can review  You can repeat this process again when there are new changes on their branch  and you will always end up with a clean set of changes  on the tip  of their branch  When you merge their branch into your branch  you tie the two branch histories together at this point  If you do this again later with more changes  you begin to create an interleaved thread of histories  some of their changes  some of my changes  some of their changes  Some people find this messy or undesirable    For reasons I don t understand  GUI tools for Git have never made much of an effort to present merge histories more cleanly  abstracting out the individual merges  So if you want a  clean history   you need to use rebase   I seem to recall having read blog posts from programmers who only use rebase and others that never use rebase   Example  I ll try explaining this with a just-words example  Let s say other people on your project are working on the user interface  and you re writing documentation  Without rebase  your history might look something like   Write tutorial Merge remote-tracking branch  origin master  into fixdocs Bigger buttons Drop down list Extend README Merge remote-tracking branch  origin master  into fixdocs Make window larger Fix a mistake in howto md   That is  merges and UI commits in the middle of your documentation commits   If you rebased your code onto master instead of merging it  it would look like this   Write tutorial Extend README Fix a mistake in howto md Bigger buttons Drop down list Make window larger   All of your commits are at the top  newest   followed by the rest of the master branch    Disclaimer  I m the author of the  10 things I hate about Git  post referred to in another answer

User · Answer

Suppose originally there were 3 commits  A B C     Then developer Dan created commit D  and developer Ed created commit E     Obviously  this conflict should be resolved somehow  For this  there are 2 ways   MERGE     Both commits D and E are still here  but we create merge commit M that inherits changes from both D and E  However  this creates diamond shape  which many people find very confusing   REBASE     We create commit R  which actual file content is identical to that of merge commit M above  But  we get rid of commit E  like it never existed  denoted by dots - vanishing line   Because of this obliteration  E should be local to developer Ed and should have never been pushed to any other repository  Advantage of rebase is that diamond shape is avoided  and history stays nice straight line - most developers love that

User · Answer

I really love this excerpt from 10 Things I hate about git  it gives a short explanation for rebase in its second example       3  Crappy documentation      The man pages are one almighty    f    you   1  They describe the commands from the perspective of a computer scientist  not a user  Case in point   git-push     Update remote refs along with associated objects       Here   s a description for humans   git-push     Upload changes from your local repository into a remote repository       Update  another example   thanks cgd   git-rebase     Forward-port local commits to the updated upstream head       Translation    git-rebase     Sequentially regenerate a series of commits so they can be               applied directly to the head node    And then we have   git-merge - Join two or more development histories together    which is a good description     1  uncensored in the original

User · Answer

For easy understand can see my figure   Rebase will change commit hash  so that if you want to avoid much of conflict  just use rebase when that branch is done complete as stable

User · Answer

Git rebase is closer to a merge  The difference in rebase is    the local commits are removed temporally from the branch  run the git pull insert again all your local commits    So that means that all your local commits are moved to the end  after all the remote commits  If you have a merge conflict  you have to solve it too

User · Answer

While the accepted and most upvoted answer is great  I additionally find it useful trying to explain the difference only by words   merge      okay  we got two differently developed states of our repository  Let s merge them together  Two parents  one resulting child       rebase      Give the changes of the main branch  whatever its name  to my feature branch  Do so by pretending my feature work started later  in fact on the current state of the main branch        Rewrite the history of my changes to reflect that      need to force-push them  because normally versioning is all about not tampering with given history     Likely    if the changes I raked in have little to do with my work    history actually won t change much  if I look at my commits diff by diff  you may also think of    patches           summary  When possible  rebase is almost always better  Making re-integration into the main branch easier   Because    your feature work can be presented as one big    patch file     aka diff  in respect to the main branch  not having to    explain    multiple parents  At least two  coming from one merge  but likely many more  if there were several merges  Unlike merges  multiple rebases do not add up   another big plus

User · Answer

I found one really interesting article on git rebase vs merge  thought of sharing it here   If you want to see the history completely same as it happened  you should use merge  Merge preserves history whereas rebase rewrites it  Merging adds a new commit to your history Rebasing is better to streamline a complex history  you are able to change the commit history by interactive rebase

[git] What's the difference between 'git merge' and 'git rebase'?

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