Git is an Open Source Distributed Version Control System.

https://medium.com/free-code-camp/what-is-git-and-how-to-use-it-c341b049ae61

https://medium.com/free-code-camp/a-beginners-guide-to-git-how-to-create-your-first-github-project-c3ff53f56861

$ git clone [HTTPS Address]

When you want to save your work, four steps are required. These steps are called: "status", "add", "commit" and "push".

$ git status

$ git add [Filename] [...]

$ git commit -m "Added ..."

$ git push origin master