What are smart contracts?

Smart contracts are self-executing digital agreements written in computer code that exist on blockchain networks. They have become an essential technology in the continued emergence of cryptocurrency, playing a key role in the creation and inner workings of decentralized applications (DApps).

A closer look at smart contracts

Smart contracts are coded digital agreements written to blockchain networks. Once deployed, they typically cannot be changed or deleted. This technology significantly reduces the need for trusted intermediaries when creating and enforcing agreements. Unlike traditional contracts that require lawyers to draft and mediators to oversee disputes, smart contracts' terms are written in publicly auditable, immutable code that automatically executes when specific conditions are met.

These digital agreements serve as the building blocks of decentralized applications (DApps). Their interoperability allows them to be stacked, creating increasingly sophisticated products that function without oversight or involvement from intermediaries, including their creators. This characteristic has led to the phrase "money lego" being used to describe smart contract-based applications.

The origins of smart contracts

The concept of smart contracts was first introduced by Nick Szabo, a cryptographer, computer scientist, and early digital-money pioneer. In a 1994 essay, Szabo described computerized agreements that would automatically execute when predefined conditions were met. However, the technology to implement these contracts was not available at the time.

The creation of Bitcoin later provided the necessary technological foundation for smart contracts. While Bitcoin allows for simple smart contracts, more sophisticated programming languages are typically used for writing most smart contracts. Platforms like Ethereum, Solana, Avalanche, Polkadot, and Cardano support the development of DApps built using smart contracts.

Ethereum, launched in 2015, is widely credited with bringing smart contracts to the crypto space. The project aimed to extend the functionality of the pioneering blockchain technology introduced by Bitcoin in 2009. Ethereum's smart contracts run on the Ethereum Virtual Machine (EVM), a digital software responsible for code execution and smart contract deployment.

How smart contracts work

Smart contracts are written in programming languages such as Solidity, Vyper, and Rust, with Solidity being the most popular for coding Ethereum-based smart contracts. These languages are used to build smart contracts with predefined rules and logic, often following the simple structure of "if X happens, then do Y".

Once written, the code is compiled into a machine-readable format called bytecode. The blockchain can understand bytecode and execute the rules of the smart contract accordingly. As users interact with a contract, the blockchain responds by automatically executing the correct action through a transaction. These transactions are paid for using gas fees.

How smart contracts are used

Smart contracts have become the cornerstone of much blockchain innovation in recent years. They have enabled developers to monetize digital artwork and collectibles, and are instrumental in decentralizing the financial (DeFi) industry. Some notable examples of smart contract applications include:

1. Aave: A decentralized, non-custodial borrowing and lending protocol that allows users to earn returns and borrow assets by depositing assets into liquidity pools.

2. Civic: A personal identity verification service that provides secure and low-cost identity verification services, giving users total access to and control over their personal identity information.

3. Uniswap: A leading decentralized exchange that relies on smart contracts for the smooth operation of liquidity pools within its automated market makers.

The final word

Smart contracts are undeniably the backbone of the modern crypto space, fundamental to the operations of DApps and the pioneering projects built around them. By removing the need for centralized intermediaries, this technology supports a key pillar of cryptocurrency: decentralization. As demonstrated by the examples provided, smart contracts are being used in diverse ways, with new use cases continually emerging. Their importance to the industry cannot be overstated, and they will likely continue to play a crucial role in shaping the future of blockchain technology and decentralized finance.

FAQ

What is smart contract in simple words?

A smart contract is a self-executing digital agreement stored on blockchain. It automatically enforces rules and conditions without intermediaries.

Is Bitcoin a smart contract?

No, Bitcoin itself is not a smart contract. However, Bitcoin supports basic smart contract functionalities through its scripting language, enabling programmable transactions like multi-signature wallets and time-locked transactions.

What is an example of a smart contract in real life?

A real-life example is Aave, a decentralized lending platform where users can lend and borrow cryptocurrencies automatically through smart contracts, without intermediaries.