0x (ZRX) is a protocol that enables two parties to trade Ethereum tokens directly without having to go through a third-party exchange. The protocol is based on the Ethereum blockchain, and it uses smart contracts to facilitate the trading process. In addition, the protocol also provides a decentralized exchange (DEX) where traders can buy and sell tokens in a secure, trustless environment.

The main goal of 0x is to provide a fast, secure, and cost-effective way to trade tokens. To do this, the protocol utilizes a system of off-chain order books and on-chain settlements. The off-chain order books are maintained by relayers, who are responsible for broadcasting the orders to the network and executing trades. The on-chain settlements are performed by the Ethereum blockchain, which ensures that the trades are secure and immutable.

In addition to facilitating the trading process, 0x also provides a governance system that allows the community to propose and vote on protocol upgrades. This helps to ensure that the protocol remains up-to-date with the latest developments in the Ethereum ecosystem.

Overall, 0x is an important protocol that is transforming the way Ethereum tokens are traded. By providing a secure and trustless environment for traders, the protocol is helping to foster a vibrant and prosperous token trading ecosystem.