We often praise the genius of "smart contracts" and say they are self-executing code that runs automatically without intermediaries. For example: "If the price of Bitcoin reaches $100,000, sell my coins."
But there is a serious secret that many people don’t know: the blockchain is completely "blind"! Networks like Ethereum or Binance Smart Chain cannot connect to the regular internet (Web2). They can’t open Google to check the weather, and they can’t access trading platforms to know the current Bitcoin price. So how do smart contracts execute their conditions if they are isolated from the outside world?