Tether USDT is a type of cryptocurrency known as a stablecoin. It is designed to maintain a stable value by being pegged to a reserve of fiat currency, such as the US dollar, at a 1:1 ratio. This means that for every USDT token issued, there should be an equivalent amount of US dollars held in reserve. Tether USDT can be used for transferring value quickly and securely on the blockchain, trading on exchanges, and as a store of value.