How options actually work on binance?

So, often when shopping for bitcoin I arrange shopping for orders at specific prices. I was speaking about this with a pal who buys stocks using choices, and he stated:

You may promote places at the strike you needed to purchase, if the worth is on the money, you purchase the asset at the worth you needed, if its out of the money you get the premium.

Wich is cheap, I did a check with a small sum of money and bought a put, but because it was out of the cash the the contract expired I only stored the premium, what happens if the contract expires on the cash?