Understanding Cryptocurrency, Wallets and DApps

This workbook bridges foundational blockchain knowledge to practical application development, guiding second-year students through creating smart contracts and decentralized applications. Day One introduces smart contracts as automated "if-then" logic-like vending machines guaranteeing soda delivery without human intervention. Students explore the Ethereum Virtual Machine (EVM) as a "World Computer" and learn why Gas prevents network-crashing infinite loops while making code efficiency economically crucial. Day Two transitions to hands-on Solidity programming using Remix IDE. Beginning with SimpleStorage (blockchain's "Hello World"), students progress to implementing security through the Owner pattern, discovering how msg.sender provides cryptographic authentication and require statements enforce access control. Day Three culminates in asset creation-building ERC-20 fungible tokens and ERC-721 NFTs using OpenZeppelin standards. The final session connects contracts to users through MetaMask wallets, revealing that wallets store keys, not coins, and that cryptographic signatures replace passwords in Web3.