The PDF in this folder is an abbreviated version of the Bitcoin white paper paraphrased by Justin Huang. It also has a few notes including more contemporary terminology, such as the blockchain and mining. The original LaTeX file is also here, if you're curious.
If you would like to read the original (which we highly recommend), follow this link.
Additionally, 3Blue1Brown has a good video on the topic, which covers a lot of material from the white paper, found here.