Questions to be answered
What is the difference between Git and GitHub?
What is the difference between a commit and a push?
What is the typical workflow of pulling modified files off of github, making changes and pushing the changes back to the github repository?

- Git is a version control system, while GitHub is an online service holding repositories for teamworks.

- Commits are used to push changes to local repositories, while pushing is used to upload local commits to remote repositories.

- First you want to make the local repository the same with the remote one, which is the pulling step. Then you make commits to a separate branch after modifying files. Push the branch, and then you're ready to create a new pull request.