Says its lecture notes right at the top.

  > "Think of these lecture notes as a living textbook that strives to strike a..."

Why would you need to watch a video on lecture notes?

Because lecture notes on these subjects without the accompanied lectures are an awful way to learn the material. This web site offers little value.

Well two things:

1. Maybe you aren't the intended audience for this.

2. They are lecture notes and homework which are typically distilled from a textbook or industry experience topic.

These are helpful items for someone teaching or speaking to these topics, you aren't supposed to directly learn from the notes. Its the equivalent of saying you could learn c++ from a power point presentation.