I use the following command to push to my remote branch:

git push origin sandbox

If I say

git push origin

Does that push changes in my other branches too, or does it only update my current branch? (I have three branches: master, production and sandbox).

(The git push documentation is not very clear about this, so I'd like to clarify this for good)

What branches/remotes do the following git push commands exactly update?

git push 
git push origin

("origin" above is a remote)

(I understand that "git push [remote] [branch]" will push only that branch to the remote)