Elementary Track 04
🏧
Vending Machine & Contracts
A vending machine dispenses a drink automatically when conditions are met. Insert money, get a drink — no trust or intermediary needed.
What You'll Learn
- → What smart contracts are and how they differ from traditional agreements
- → Core Solidity structure — state variable, function, event, modifier
- → The lifecycle from writing to deploying, calling, and changing state
👨💼
Traditional Contract
Requires intermediaries, courts, and banks. Enforcement takes time and money.
🤖
Smart Contract
Code is the contract. Executes automatically when conditions are met. Immutable.
⛓️
On-chain Storage
Every node holds a copy. Censorship-resistant. Anyone can verify the code.
💡 Nick Szabo proposed the "smart contract" concept in 1994. Ethereum (2015) was the first to implement general-purpose smart contracts.