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Smart Contracts are similar to paper contracts of the analogue world but instead of ink on paper, they are written as digital text in computer-readable code. Smart contracts are usually eternal, meaning they are not “closed” and deleted after their execution. When executed, both the programs in your PC and blockchain smart contracts (which are also programs) do what they have been designed to do, assuming there are no software bugs. Using an interface such as MetaMask, a smart contract is triggered using a blockchain transaction that connects to a node.