In Git, what is the difference between origin/master vs origin master?

Question

I know, origin is a term for the remote repository and master is the branch there.

I am purposely omitting the "context" here and I am hoping that the answer should not depend upon the context. So in git command lines, what is the difference between origin/master and origin master. Is there a non-ambiguous way to understand when to use origin/master and when I should use origin master?

Answer 1

There are actually three things here: origin master is two separate things, and origin/master is one thing. Three things total.

Two branches:

• master is a local branch
• origin/master is a remote branch (which is a local copy of the branch named "master" on the remote named "origin")

One remote:

• origin is a remote

Example: pull in two steps

Since origin/master is a branch, you can merge it. Here's a pull in two steps:

Step one, fetch master from the remote origin. The master branch on origin will be fetched and the local copy will be named origin/master.

git fetch origin master

Then you merge origin/master into master.

git merge origin/master

Then you can push your new changes in master back to origin:

git push origin master

More examples

You can fetch multiple branches by name...

git fetch origin master stable oldstable

You can merge multiple branches...

git merge origin/master hotfix-2275 hotfix-2276 hotfix-2290