Hey, Codey here. This content is described as Unit Zero as it is not a set of formal lessons. Instead, it is a set of interesting videos and discussions that you can use to intermingle throughout the coding units of the course.  

Some videos cover specific AP content.  Others just discuss the power and impact of algorithms on modern life.

They are grouped in 2 sets mirroring the Big Ideas of Algorithms and Global Impact.   The videos can be intermingled and should be peppered in throughout the year in order to cover all the course content.