Trading bitcoin/ethereum, what is a golden/death cross? A moving average analysis on today's price

Market is moving fast and I am holding my long from two days ago, but I have been crunching these short videos like nobody's business. This one is also going to be on the moving averages like the last one. More specifically, I will be analyzing the golden cross and death cross of a moving average as a signal for entry. I want to make it less than 5minute so you can move on with your day and learn something new if you haven't already.