What is the difference between USDT and BUSD?

Could you elaborate on the distinctions between USDT and BUSD? As I understand, both are stablecoins pegged to the US dollar, but I'm curious about their backgrounds, issuance mechanisms, and any other key differences that might affect their usage or adoption in the cryptocurrency ecosystem. For instance, who are the issuers of these coins, and how do they ensure their stability? Also, are there any differences in terms of transaction speed, fees, or liquidity? Your insights would be greatly appreciated.