DAI is a stable cryptocurrency issued on the MakerDAO platform that maintains a fixed value equal to one US dollar (1 DAI ≈ 1 USD). Unlike other stablecoins such as USDT or USDC, which are backed by real dollars in a bank, DAI is backed by collateral in the form of various crypto assets such as Ethereum. Users can deposit their crypto assets into MakerDAO smart contracts to issue DAI, with the entire process being decentralized and managed by a community of MKR token holders. Due to its decentralized nature and transparency, DAI is popular in various DeFi applications, bringing stability and accessibility to the world of cryptocurrencies.