After you're done with a branch (your modifications have been pulled in to another branch, or you don't need them anymore) you should delete it to avoid lots of branches cluttering things up.
Firstly, deleting a branch locally is pretty simple:
git branch -d [branchName]
If the branch has been pushed to a remote repo, you'll want to delete the remote version of the branch too. This can be done thus:
git push [remoteName] :[branchName]
In the above, [remoteName] will likely be origin, as that is the default alias set up in your local repo to track the remote repo it was cloned from. That colon in front of the branch name actually tells Git to delete the branch.
Pruning deleted remote branches is probably something you'll want to do as well. When others delete a branch remotely as described above, you're unlikely to want to keep it around on your local repo. A git pull will not cause their remote references to be deleted on your local repo. To do that, you need to run:
git fetch --prune --prune-tags
Note that combining --prune with --prune-tags does exactly the same kind of pruning for local tags - removes them if they've been removed remotely. To avoid having to remember this command, you can setup a handy alias to prune branches for the remote name you usually (or always) use by adding a section like the following to your global Git config:
[alias]
doprune = fetch --prune --prune-tags
Note that while this will automatically prune tracking branches when you run git doprune, you'll have to manually delete any local non-tracking branches you've setup to mirror the remote branch. For example:
$ git branch
* master
my-new-feature
$ git fetch --prune --prune-tags <-- (or git doprune)
From https://bitbucket.org/my/repo
- [deleted] (none) -> origin/my-new-feature
$ git branch
* master
my-new-feature <-- (non-tracking branch still here!)
$ git branch -d my-new-feature
Deleted branch my-new-feature (was d175c79).
$ git branch
* master