A Promise is a value not necessarily known at the time of it's creation. It mainly used in asynchronous actions resulting in success or failure. The Promises represents a value which may be available now, or in the future, or never.
With HTML5 Video Tag it is very easy and simple to include video in page. Unlike earlier we had to include Flash object and to support that we need to add Flash Player Plugin in browsers.
Useful tips on @mixin for SASS for the Breakpoint. I have updated the @mixin for the breakpoint to include any last minute changes to target any width/viewport just by entering the pixel width at the time of @include.