The preceding steps described the major purpose of blockchain and the relation between trust and the integrity of software systems. As a result, you gained a well-grounded appreciation of the purpose of blockchain, but a definition of the term “blockchain” itself is still missing. This step turns our attention to blockchain and explains its different usages. It presents a provisional definition, which will guide you through the remainder of this book. Finally, this step explains why ownership management is a prominent use case for blockchain.