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So, you want to know what a smart contract is, and why you should care?

Well, start with this. Smart contracts are what turned crypto into an industry.

Bitcoin may be the largest and best-known cryptocurrency, but other than it — and few other pure cash-replacements coins like litecoin, and stablecoins like tether and USD coin — every token runs on a blockchain that can properly be called a smart contract platform.

Smart contracts are the building blocks of decentralized finance, or DeFi. And non-fungible tokens (NFTs), and blockchain-based games, and streaming video platforms, and social media sites — well, you get the picture.

At the high level, smart contracts are what is threatening to upend big finance, reimagine the supply chains that move goods around the world, and even provide the foundation for the next-generation Web3 that supporters hope will end big tech’s dominance of the internet.

Smart contracts were brought to blockchain in 2015 with the launch of Ethereum, which is more properly known as a smart contract platform — despite the fact that its token, ether, is now the second-largest cryptocurrency with a market capitalization of more than half a trillion dollars. This gives you a sense of how important smart contracts are.

Immutable Agreements

More prosaically, smart contracts are agreements written on blockchains that run without any outside approval or human input when conditions are met. They are “self-executing” contracts.

The point is that once they have been written and agreed to, they are immutable — the terms cannot be changed or the agreement canceled. Any payment stipulated in the contract is locked into the contract at its creation, so there is no getting your crypto back, either.

This removes the need for a trusted intermediary to ensure that the terms of an agreement are enforced, such as Visa, which a merchant trusts to be sure they will be paid, and a customer trusts to make sure their goods will be delivered and not be defective.

Take a simple example from DeFi. Tom wants to borrow $10,000, so he goes to a lending protocol, and sets up a smart contract. Tom agrees to deposit $15,000 worth of ether (or another cryptocurrency) — 150% of what he is borrowing — as collateral into the contract, in exchange for $10,000 in stablecoins.

Caveats

The agreements are written in the “if-this-then-that” language of computer coding, so there are a few very big caveats to that whole “replacing trust” idea.

For one thing, just like computer code can be buggy, a smart contract’s language can have very nasty surprises if it doesn’t say what you think it does. Remember, once the contract is agreed to and locked, there’s no going back in to correct mistakes. The crypto industry term is “code is law” — which roughly translates to “get it right the first time, or else.”

Because smart contracts eliminate the need for trust, and because cryptographers should never be allowed to name anything the general public will use, they are called “trustless.”

轉貼自： pymnts

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