Compound is a DeFi lending protocol that allows users to earn interest on their cryptocurrencies by depositing them into one of several pools supported by the platform.

When a user deposits tokens to a Compound pool, they receive cTokens in return. These cTokens represent the individual’s stake in the pool and can be used to redeem the underlying cryptocurrency initially deposited into the pool at any time. For example, by depositing ETH into a pool, you will receive cETH in return. Over time, the exchange rate of these cTokens to the underlying asset increases, which means you can redeem them for more of the underlying asset than you initially put in — this is how the interest is distributed.

USDT is a stablecoin (stable-value cryptocurrency) that mirrors the price of the U.S. dollar, issued by a Hong Kong-based company Tether. The token’s peg to the USD is achieved via maintaining a sum of commercial paper, fiduciary deposits, cash, reserve repo notes, and treasury bills in reserves that is equal in USD value to the number of USDT in circulation.

Originally launched in July 2014 as Realcoin, a second-layer cryptocurrency token built on top of Bitcoin’s blockchain through the use of the Omni platform, it was later renamed to USTether, and then, finally, to USDT. In addition to Bitcoin’s, USDT was later updated to work on the Ethereum, EOS, Tron, Algorand, and OMG blockchains.

The stated purpose of USDT is to combine the unrestricted nature of cryptocurrencies — which can be sent between users without a trusted third-party intermediary — with the stable value of the US dollar.