It's basically the same thing if you still confused. USDT is a digitalized version of the USD fund reserved by the company tether the price fluctuation or gap is just because the buy and sell request kinda massively dumped at the same time.
Do USD and USDT have more or less or the same thing in terms of the price difference? please suggest because I am planning to buy some USDT.
Why do you want to buy USDT? because USDT is a stable coin, therefore I would advise you to save USD rather than USDT, because USD is real money, so I suggest you to buy another cryptocurrency to be used as an investment, so that you can get a big profit from investing in cryptocurrency.
Well maybe because he wants to buy USDT for the sake of convenience when it comes to buying cryptos? I'm pretty sure that the existence of USDT alone is a proof that having USD is kinda hard to deal when you want to buy crypto and it's not always about investment. Sometimes people using USDT for the sake of sending money to someone they know or in other word remmitance.