Cryptocurrencies, blockchain, smart cities, smart contracts – you probably encounter these terms almost daily in the media. We are currently in a world that is rapidly advancing due to technological developments. Everything is supposed to be interconnected in the wake of the Internet of Things. Additionally, new financing models, such as Initial Coin Offerings, are helping startups finance their innovative projects. But what do all these terms mean? What exactly is an Initial Coin Offering? How does the Proof-of-Work algorithm differ from the Proof-of-Stake algorithm? What should be considered regarding the taxation of cryptocurrency trading? This book will guide you through these topics. It provides a concise summary of fundamental knowledge about blockchain, including an explanation of ICOs and the applications of blockchain today and in the future.