What is USDT used for?

Could you please explain to me what USDT is primarily utilized for? I've heard it mentioned frequently in the context of cryptocurrency and finance, but I'm still hazy on its exact purpose. Is it a means of exchange, a store of value, or perhaps both? Additionally, how does it differ from other cryptocurrencies? Is it widely accepted in the market, and if so, what kind of transactions does it facilitate? I'm quite interested in understanding the role and significance of USDT in the crypto ecosystem.