Status checks let you know if your commits meet the conditions set for the repository you're contributing to.
Status checks are based on external processes, such as continuous integration builds, which run for each push you make to a repository. You can see the pending, passing, or failing state of status checks next to individual commits in your pull request.
You can see the overall state of the last commit to a branch on your repository's branches page or in your repository's list of pull requests.
If status checks are required for a repository, the required status checks must pass before you can merge your branch into the protected branch. For more information, see "About required status checks."
Organization owners and users with push access to a repository can create statuses with GitHub Enterprise's API. For more information, see "Statuses" in the GitHub Developer documentation.