Git- some how a single branch having two names created how do i make it single - git-branch

Question

I just tried to rename the branch with following command
git branch -m <oldname> <newname>
my older branch name is feature/AAM-443 and this branch is already merged with parent now when i renamed it with feature/AAMN-443 and push it to remote then the branch in network is showing
*<commit id> feature/AAM-443, feature/AAMN-443
and if i do some commit to feature/AAMN-443 then graph is like
* <new-commit id> feature/AAMN-443
|
|
* <old-commit id> feature/AAM-443
what is happening i am wondering that what the meaning of a branch having two names is it some symbolic reference and why the feature/AAM-443 is still there why not it removed can anyone help

Answer 1

To add to #RomainValeri's answer, a branch can't have two names, so what you did was this:
You had a remote tracking branch:
git branch -a
feature/AAM-443
origin/feature/AAM-443 <-- tracked by feature/AAM-443
You renamed your branch locally:
git branch -m feature/AAM-443 feature/AAMN-443
git branch -a
feature/AAMN-443
origin/feature/AAM-443 <-- still thinks it's tracked by feature/AAM-443
You pushed your renamed branch to origin:
git push -u feature/AAMN-443
git branch -a
feature/AAMN-443
origin/feature/AAMN-443 <-- tracked by feature/AAMN-443
origin/feature/AAM-443 <-- no longer tracked by any local branch!
Then you made a new commit and pushed:
git commit -am "new commit" <-- on branch feature/AAMN-443
Your remote repo updated like this:
o <-- origin/feature/AAMN-443
|
o <-- origin/feature/AAM-443 (branch is no longer tracked! It has been left behind!!)
Like #RomainValeri said, you need to delete origin/feature/AAM-443:
git push --delete origin feature/AAM-443

Answer 2

You just have to remove the remote counterpart that's still there.
(assuming your remote is named origin here)
git push --delete origin feature/AAM-443
# or
git push origin :feature/AAM-443