Blockchain is an immutable digital ledger system that eliminates the need
for centralized storage and authority, enabling decentralized financial transactions. It is
made up of timestamped, immutable information blocks that are managed by a
collection of nodes rather than by any one node. Using cryptographic methods, every
block is connected and secured. Blockchain provides a secure and transparent solution
by redefining faith, possession, and identity in financial systems. This chapter
thoroughly reviews blockchain technology, focusing on why we need it. Next, the
chapter discusses blockchain technology's characteristics, type, architecture, and work.
Further, the chapter presents some areas of application and challenges it faces.
Keywords: Blockchain, Blockchain technology, Bitcoins, Cryptocurrency, Decentralization, Public blockchain, Private blockchain, Smart contracts, Security, Transparency.
