A simple URL link.
[Google](https://www.google.com)
A URL Reference link. Reference name and it's url can be placed at the bottom of the markdown file.
[Link Text][reference name]
[Another Text with same reference link][reference name]
[External Link][google]
[Internal Link][about]
[reference name]: http://www.test.com
[google]: https://www.google.com
[about]: /about