why does this need to be two hours?

Most of the 2 hours are spent on intro, telling a story as to why you are here, and the history of windows. I know this because EVERY TUTORIAL has needless information and video, they should just be “here’s how you *thing*” video of doing thing, and that’s it

It's based off of the percent of the video a certain amount of people watched. If a person watches the first 1 minute of the video, it won't count as a view because they didn't watch enough of it to count. On the other hand, if someone watches 30 minutes of it, they watched enough of it to count as a view.
I hope this simplifies it for you.

do you know the exact pecentage?

No that was just an example.

Hmmm