This chapter introduces blockchain with its fundamental topics. We thoroughly explain the blockchain components including cryptographic hash functions, blockchain transactions, asymmetric-key cryptography, block (explaining Merkle tree root, nonce), and constructing a chain of blocks. We present a visual representation of how blockchain works and explain the key characteristics of blockchain, e.g., decentralization, immutability, anonymity, auditability, and non-repudiation. We also describe the blockchain taxonomy and present a clear comparison among the public, private, and consortium blockchain. To the end, we present some examples of blockchain applications and listed the major advantages, and limitations of blockchain technology.
