0x is a messaging protocol as well as a set of smart contracts. Market makers can send messages off-chain including information about their order, such as the tokens being exchanged, the price, and the order's expiration date. A token registry, which is a smart contract that stores the list of ERC20 tokens available for exchange, keeps track of the right message format. The registry acts as the official on-chain reference for transaction settlement, allowing market participants to verify the token addresses and exchange rates at which deals will settle once conducted. Takers sign messages and the smart contracts accept them and perform the trade on-chain. The smart contracts also contain the logic that allows the protocol to be upgraded over time.
0x is built on the Ethereum blockchain. As a result of the combined efforts of the huge Ethereum miner and node network, it is safe against attacks. It also supports Solidity as its programming language.
Use of Native tokens in the ecosystem: The 0x platform's native token is ZRX. ZRX token holders have the ability to vote on any suggestions put up by the 0x team as the network develops. Each 0x coin serves as a vote, incentivizing users to keep additional 0x in their wallets. All ZRX tokens are locked during voting while the results are determined. This assures that any changes done will have a direct impact on all voters (preventing sabotage). Users can also participate in liquidity pools to gain incentives on their ZRX investments.