You should refer to this book: "Master Bitcoin" by Andreas M. Antonopoulos. This is a key book to understanding the idea and concept of a decentralized currency based in the digital world. The book goes into the technology behind bitcoin, the purpose of the virtual currency, and its applications in the real world. Readers learn how the currency works, the nature of bitcoin transactions and details about the underlying network. The book also covers some critical concepts behind bitcoin, such as the blockchain and bitcoin wallet.