50% Rule?

[Jerry Going]

Hello everyone!

So I am brand new, and basically have no idea what I'm doing. So, I decided to at least start with the free course bigger pockets offers. Love it , so far! However, I do not understand the 50% rule. Maybe I missed the explanation, because I view the course at odd times. Either way, what I don't understand is what happens to the "other 50%"? In the course (and correct me if I'm wrong, please) it explains that you take 50% of whatever the monthly payment is, and from that you subtract the mortgage. What's left over of that 50% after the mortgage is removed, is your "cash flow"? What does the other 50% go to?