Coin exchange markets create the coin "out of thin air "
You first buy the 0.0001 BTC from Binance or any local coin exchange markets.
You give 3.5 dolar to Binance and Binance add 0.0001 btc to your account.
In this transaction, really, Binance gives you BTC ?

do you mean you are doing P2P transactions with Binance itself? like when you buy crypto instantly with a credit card?
yeah, Binance will give you only numbers unless you withdraw your Bitcoin or send it outside Binance, they will give you the real Bitcoin.
Most of the exchanges use their latest price on the spot market to fulfill your instant order. They give you the Bitcoin that they buy automatically from the spot market orders. CMIIW. I am not sure about it too.