Blockchain is a technology for recording and storing digital information. It is particularly suitable to store transaction history: record a transaction in a so-called block where each block contains information about the previous block. They are all linked together into a chain. The information in the blocks is encrypted. Each blockchain segment is stored on a separate computer, i.e., it is “distributed”. There is no one repository where all the information is kept. There are many segments connected in a chain. Therefore, the blockchain is called a decentralized system.
Blockchain is widely popular for two main reasons: blocks are decentralized, which means parties are not involved in approving transactions in the chain. And secondly, the blockchain is immutable (protected from hacking) because any change requires the consent of all network participants, also known as a “consensus”.
Read more in the article blockchain in details