What is USDT?
Tether (USDT) is a digital currency whose value always matches the value of the US dollar. Tether was launched in 2014. The idea was to create a stable cryptocurrency that could be used as a digital dollar or "stablecoin". Tether is tethered (from English to tether) to the price of the US dollar.
Tether originally used the Omni Layer transport protocol of the Bitcoin network, but it is now also available as an ERC20 token on Ethereum. In total, Tether is issued on the Bitcoin (both Omni and Liquid), Ethereum, EOS and Tron blockchains.
Tether tokens are issued by Tether Limited, the CEO of which also runs the Bitfinex cryptocurrency exchange. Tether previously stated that Tether's currencies are 100% backed by Tether's reserves, but after Tether's lawyers noted in 2019 that Tether is only 74% backed, i.e. had only a partial reserve, Tether noted that the definition of full collateral includes loans to affiliated companies.