This book is mostly intended for students. If you can use a programming language, this book will teach you how cryptographic currencies work, how to use them, and how to develop software that works with them. The first few chapters are also suitable as an in-depth introduction to blockchain and bitcoin for noncoders—those trying to understand the inner workings of bitcoin and cryptocurrencies. If you can use a programming language, this book will teach you how smart contract blockchains work, how to use them, and how to develop smart contracts and decentralized applications with them. I also covered an in-depth introduction to Ethereum for noncoders.