
Smart contracts are essentially the transformation of contract logic into code, deployed on public chains such as Ethereum or BNB Chain. Once preset conditions are met, such as “receiving 1 ETH,” the ownership of the NFT is automatically transferred without the need for intervention from lawyers or banks. This disintermediation design significantly reduces costs and time, shortening the confirmation from several days to seconds, becoming the technological cornerstone of DeFi lending and NFT trading.
Once deployed, the contract becomes an immutable state machine on the Blockchain. Users call functions through wallet transactions, and the EVM virtual machine executes logic and updates the network state. Each node independently verifies, and after reaching consensus, records it in a Block, ensuring transparency and immutability. Taking Uniswap swaps as an example, slippage checks and token transfers are completed in one step to avoid double-spending risks.
In DeFi, smart contracts drive liquidity pools for automatic exchanges, Aave collateral lending, and Yearn yield aggregation, with an annualized TVL exceeding 100 billion USD; in the NFT field, it supports automatic distribution of royalties and blind box opening logic. Supply chain tracking allows for real-time on-chain status of goods, and insurance claims are automatically triggered based on weather data, demonstrating cross-industry penetration.
No need to trust third parties, contracts are the law, eliminating moral hazards and operational delays; although Gas fees exist, they are far lower than traditional transaction fees. Security comes from thousands of nodes validating and auditing, and DAO governance allows community upgrades, which is superior to the vulnerabilities of centralized databases that are easily attacked by hackers.
The biggest risk comes from programming errors, such as the 2016 DAO hack that resulted in a loss of 50 million USD, highlighting the double-edged sword of “code is law.” During high concurrency, Gas wars and congestion slow down execution, and Layer 2 solutions like Optimism are trying to address this. Legal validity still awaits recognition from various countries, limiting off-chain applications.
Smart contracts replace intermediaries with code, supporting a trillion-dollar ecosystem from DeFi to NFTs in Web3, but vulnerabilities and scalability challenges demand rigorous audits and layered solutions. With the burning of EIP-1559 and the maturity of ZK-Rollups, their efficiency will continue to improve. Beginners who grasp this foundation will understand the core value of Blockchain and embark on their dApp development journey.











