How Differential Gear works must see 100%

This is NOT the full video, cuz the full video has 4 useless minutes.. and i was looking around in all the internet to understand how it works, and i opened that video a lot of times , and i closed it , cuz i thought that it does not talk about the differential, cuz it talks about it after 4 min, so i make this useful CUT.. the original one in titled ---How Differential Gear works (BEST Tutorial)---