What is the real name of USDT?

I'm curious, could you clarify for me what the actual name of USDT is? As I understand, the term "USDT" is often used in the realm of cryptocurrency, but I'm not entirely sure if it's an abbreviation or a nickname for a particular coin or token. It would be helpful if you could elaborate on its official nomenclature, as I'm interested in gaining a deeper understanding of the financial landscape that it inhabits. Could you please shed some light on this matter for me? Thank you in advance for your assistance.