This chapter explores the revolutionary potential of blockchain technology, following its development from the early days of Bitcoin to its present use in a multitude of sectors. The chapter examines the fundamental elements of blockchain, including nodesNodes, chains, and blocks, chains, and blocksNodes, chains, and blocks, and provides mathematical models that describe broadcasting and transaction validation in decentralized networks. The chapter also looks at how blockchain can affect the economy, emphasizing how it could reduce costs, increase revenue, and manage risks. The chapter also addresses ethical issues including data privacy, legal compliance, and the environmental effects of blockchain’s consensus processes, as well as future trends like blockchain interoperability, AI integration, and sustainability.