Start to learn GitHub from today----Day1 on GitHub

What is GitHub?
----GitHub is a code hosting platform for version control and collaboration. It lets you and others work together on projects from anywhere.

GitHub essentials: repositories, branches, commits, and Pull Requests. 

Today I created my first github repository named "hello-world". I did some actions as fpllowing:

1. Create a Repository
2. Create a Branch
3. Make a Commit
4. Open a Pull Request
5. Merge Pull Request