🗄️ Blockchain

**Blockchain** is a distributed ledger behind cryptocurrencies and some decentralized apps. This course explains the technology without hype or “get rich quick” promises. You will learn how blocks, hashes, consensus, smart contracts, and wallets work at a conceptual level. The material shows where blockchain fits and where a classic database is simpler. After the course you can discuss Web3 projects thoughtfully, read whitepapers, and decide whether to dive into Ethereum or other platforms.