A contract refers to a legally binding agreement made between two parties. On the blockchain side of things, this is implemented with the introduction of smart contracts. These smart contracts are the very essence of blockchain.
This allows all transactions that occur in the blockchain to keep complete anonymity. Smart contracts are nothing but the legal binding between the buyer and seller that are directly embedded within the code.
Mining contracts are yet another integral part of any contract that blockchain-based systems use, allowing crypto miners to seamlessly work alongside the cloud services. Overall, the very sense of contract can be considered one of the fundamental components of the distributed ledger and any blockchain-based application.