About this video
Boilerplate code is no other term for handwritten code. This has been corrected on the slides but the mistake is still in the video.
Boilerplate code is code that has to be included often with little or no alteration. It appears in many places and often it can or even should be generated automatically. One example for HTML boilerplate code would be:
So, this would be something you would like to have generated automatically because it doesn't really help to write it manually which also increases the risk of making a typo and thus causing an error.