This video is covering set of more advanced features for when working with Templates in Umbraco.
You can learn more about the options that Razor gives you in this chapter:
Umbraco 7 - Razor syntax
(Note: It's a Umbraco 7 video - a Umbraco 8 version is in production)
For more information about Templates:
This series will cover the basics of how to work with Templates in Umbraco and get your HTML markup into the CMS and on to the frontend.