A blockchain is a decentralized immutable ledger composed of a series of blocks that store a set of data on transactions made in a particular network of computers, which are called nodes. Each node holds a copy of the blockchain and confirms the validity of the transactions made in it in a process called mining, or in other cases, staking.
A blockchain can be analogous to a bank ledger, except it is open, immutable, transparent, and decentralized, meaning anyone can participate in the network or view the transactions made on-chain. Furthermore, it is extremely difficult if not impossible to cheat the system since anyone who attempts to change the information stored in their version of the blockchain will simply be invalidated by all other nodes. This ensures that the blockchain remains tamper-free.
Cryptocurrencies run on blockchain technology and can be described as a use case of blockchain. Apart from crypto, blockchain offers a plethora of advantages for almost any business or industry and is disrupting the reliance of centralized datakeeping. Blockchain can be used to facilitate decentralized voting, health records, education, file sharing, governance, provenance and loyalty rewards to name a few applications.