I don't know that anyone's Cheerio's got pissed on. I will however say that there are some very basic common sense things in this world. One of them is if you buy a piece of equipment that is new to you, R.T.F.M.
If the OP had done that, I doubt that this whole thread would have existed. And before someone jumps on me about being mean spirited in answering questions, there is a world of difference between the OP's question here and one where the person asking has read the manual, or other appropriate materials and is asking about a concept they do not understand AFTER they did some basic research. We all run across concepts in our lives that even after doing some research we need help understanding. That is part of life, but failing to do that simple step in the middle is another matter.
You know what you call a guy who buys a Table Saw and doesn't read the manual?.......................................................................Stubby.