Seeing as the uploader couldn't be arsed answering your question and it was also my immediate question when starting to watch this vid.... I did some googling and the answer is "Power Take off" - "A power take-off or power takeoff (PTO) is one of several methods for taking power from a power source, such as a running engine, and transmitting it to an application such as an attached implement or separate machine".
What does PTO stand for?
Seeing as the uploader couldn't be arsed answering your question and it was also my immediate question when starting to watch this vid.... I did some googling and the answer is "Power Take off" - "A power take-off or power takeoff (PTO) is one of several methods for taking power from a power source, such as a running engine, and transmitting it to an application such as an attached implement or separate machine".