USDT (full name Tether USD). It is a stablecoin issued by Tether, formerly known as Realcoin, which is registered in the isle of man and Hong Kong. USDT is the stable currency with the highest market share on the market. It was originally issued as a cryptocurrency based on the Omni protocol, which can be simply understood as the USDT based on bitcoin.
Omni-USDT is stored on the bitcoin address, so the type of fee to be paid for each transfer is bitcoin. The address is 1 or 3 at the beginning, for example:1NTMakcgVwQpMdGxRQnFKyb3G1FAJysSfz. It is important that to successfully transfer Omni-USDT on the blockchain, there must be at least 0.0002 bitcoins in the address. At the same time, for each Omni-USDT transfer, a small amount of BTC transfer will be generated accordingly. In other words, when we made an Omni-USDT transfer on the blcokchain, two transfers "Omni-USDT and small BTC" actually took place.
Tip: there are currently BTC, ETH, TRX and EOS that support the USDT.