Default behavior of “git push” without a branch specified

Question

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

git push origin sandbox

If I say

git push origin

Answer 1

I just committed my code to a branch and pushed it to github, like this:

git branch SimonLowMemoryExperiments
git checkout SimonLowMemoryExperiments
git add .
git commit -a -m "Lots of experimentation with identifying the memory problems"
git push origin SimonLowMemoryExperiments