Blockchain is an information technology solution for distributed digital record. Its main properties are secure, traceable, and transparent. Blockchain was first proposed for bitcoin, a decentralized virtual digital currency. Recently, blockchain draws attentions of researchers, entrepreneurs, and investors, because people found that blockchain technology can revolutionize many business practices. This paper describes the fundamentals of blockchain technology, including data structure, data distribution, and transaction execution and validation. This paper also discusses the representative blockchain protocols and development platforms. In addition, this paper outlines the potential applications of blockchain technology and the broader impact it might bring to industry, business, and beyond.