Can someone explain why when depositing Bitcoin to an exchange, it sometimes generates new, but sometimes gives old (user have already deposited there) address? Or creates a different address for each user who deposit? Why not just make a few hundred of address and ask users to deposit only there? Instead, for example Binance, has 15,000,000+ users worldwide. Means exchange manage minimum 15 million address. I understand this is all security measures, but dont understand why manage so many addresses.