Serum is a decentralized exchange built on top of Solana facilitating the trading of tokens. The exchange allows for cross-chain trading and utilizes an order book unlike AMMs like Uniswap. All aspects of Serum are decentralized, a feat that can not be achieved on many L1s, only possible thanks to Solana's 400ms blocktime and low fees. Anyone can build a frontend GUI on top of the Serum order book, which aggregates all the liquidity and executes trades. Serum aims to bring DeFi to a billion users. Serum hopes to build margin trading, borrowing/lending capabilities, a stable coin, and more cross chain swaps in the future.

Serum itself does not offer a frontend UI to interact with, instead, opting to allow anyone to create a front end with all liquidity across UIs going through the Serum order book and trade execution. Anyone with technical skills can interact with the smart contracts themselves.