[[ch00_intro_what_is_bitcoin]] == Introduction === What is Bitcoin? Bitcoin is digital money, a currency for and of the Internet. It is not owned or controlled by any company, group or country. It exists as a set of standards and reference software and as a running network with several thousand nodes worldwide. Behind the scenes, bitcoin is a network, a protocol, a standard and a currency. For now think of it simply as digital money that can be sent, received and stored by anyone, worldwide simply by downloading compatible software and joining a network. Under the hood, bitcoin is the culmination of decades of research in cryptography and distributed systems and represents four key innovations brought together in a unique and powerful combination. Bitcoin consists of a de-centralized peer-to-peer network, a public transaction ledger, a de-centralized mathematical and deterministic currency issuance, a de-centralized transaction verification system and a set of powerful APIs. All of these are "bitcoin", and each of these aspects of bitcoin will be examined in this book. More than all of these parts, bitcoin is a digital economy platform, just like the Internet is a digital communications platform. With bitcoin, it is possible to build entire new financial systems, transaction types and economies on top of a purely digital, instantaneous and frictionless platform, an Internet for money. ==== A currency ==== A network and protocol ==== A distributed ledger ==== Proof of work and distributed issuance (mining) ==== A transaction language ==== An API === Getting Bitcoin ==== Obtaining the bitcoin software ==== bitcoin-qt, bitcoind ==== mobile client === History of bitcoin ==== A brief history of money ==== A brief history of crypto currencies ==== Public key cryptography and crypto-currency ==== Peer-to-Peer networks === The history of bitcoin ==== Why would I use bitcoin ===== As a merchant ===== As a consumer ===== As a developer, integrator ===== As an entrepreneur ===== As an investor