Blockchain technology has emerged as a groundbreaking innovation, offering a decentralized, transparent, and secure method for recording digital transactions and data exchanges. Initially developed to support cryptocurrencies such as Bitcoin, the technology has evolved into a versatile tool applicable across multiple sectors including construction, healthcare, finance, and public administration. This chapter explores the fundamental concepts, architecture, and evolution of blockchain technology, tracing its development from Blockchain 1.0 focused on digital currency to the more sophisticated applications in Blockchain 3.0 and beyond. Key components such as blocks, hash functions, distributed ledgers, and consensus mechanisms are examined to provide a detailed understanding of how blockchain operates. The chapter further highlights the different types of blockchain systems—public, private, and consortium—and their respective characteristics, strengths, and use cases. Additionally, the inherent features that distinguish blockchain, such as immutability, autonomy, timestamping, and peer-to-peer relationships, are discussed in the context of their value for innovation and digital transformation. By drawing on scholarly insights and technical perspectives, this chapter provides a comprehensive overview of blockchain’s foundational principles and its expanding role in shaping the digital economy.