The basic concept of blockchain is that it is a distributed database that maintains a continuously growing list of ordered records.
The growing list of records is called blocks, which are linked and secured using cryptography. Each block contains a cryptographic hash of the previous block, a timestamp and transaction data.
It is an open distributed ledger that can record transactions between two parties efficiently and in a verifiable way.
a distributed ledger, a blockchain is typically managed by a peer-to-peer network collectively adhering to a protocol for inter-node communication and validating new blocks. Once recorded, the data in any given block cannot be altered retroactively without the alteration of all subsequent blocks, which require the consensus of the network majority.