UNI is the governance token for Uniswap. UNI was introduced on 16th September 2020 through a retrospective airdrop to users who have interacted with the protocol either by swapping tokens or by providing liquidity.
The UNI token allows token holders to participate in the governance of the protocol. Key decisions such as usage of the treasury or future upgrades can be decided through a governance vote.
Uniswap is a decentralized exchange (DEX) that makes it easy for users to swap an ERC-20 token for another ERC-20 token without the need of a centralized intermediary. With a DEX, traders do not have to deposit their tokens on an exchange and be exposed to the security risks of a centralized exchange.