Blockchain is a novel decentralized technology that is used to share, replicate, and synchronize data across different geographical locations. It guarantees a trusted transaction in any untrustworthy environment. There is no central administrator or central authority to control all the data-related aspects of blockchain technology. A blockchain network depends on the consensus algorithm that must be agreed upon by all the entities for any new transaction. There are numerous advantages of blockchain, such as security, trust, open source, traceability, transparency, and many more, which make it very popular to apply in different sectors. This chapter first covers all the technologies behind blockchain. Then, some fundamental aspects of blockchain, such as types of blockchain, features, advantages, and disadvantages have been discussed. Many applications of blockchain technology in several sectors are presented in this chapter in order to demonstrate its functional value. Finally, some challenges in the adoption of blockchain technology have been discussed, which can be beneficial for researchers doing their research in blockchain.
