What is a blockchain and ethereum?

Blockchain: Blockchain refers to the system that is responsible for recording the information in a format that makes it impossible or difficult to hack, cheat or change the system.  A blockchain usually refers to the digital ledger of the transactions that is either distributed or duplicated  across the network of the computer systems on the blockchain. Blockchain is a type of the distributed ledger technology which records the transactions with an immutable cryptographic signature called hash. Each block in the chain consists of the transaction. Every time the transaction occurs, the record of the transaction will be added to every participant’s ledger.

Ethereum: Ethereum is one of the blockchain features, a decentralized software platform that is used for its cryptocurrency. It is responsible for enabling the smart contracts and the distributed applications to ensure that they are built and run without any fraud, control, downtime or any other interference from the third party. Ethereum is also referred to as a programming language that helps in running the blockchain , allowing the developers to publish and build the distributed applications.