Sushi (SUSHI) is a decentralized cryptocurrency that operates on the Ethereum blockchain. It is primarily used within the SushiSwap platform, a decentralized exchange for swapping various cryptocurrencies. SUSHI tokens can be used for governance voting and staking within the SushiSwap ecosystem. The project was created as a fork of the popular decentralized exchange Uniswap, with the goal of offering additional features and incentives for users.