Blockchain is a distributed system that acts as an «open book» to store and manage transactions or information. The records, as defined in International Records Management (ISO 15489-1: 2016) are «information created, received and maintained as evidence and as an asset for an organization or person, in compliance with legal obligations or in the business transaction.» Each record in the database is called a block and contains details such as the time stamp of the transaction and the link to the previous block or record.
These records are immutable, so it is impossible to alter or modify the information retroactively. In addition, because the same transaction is recorded in multiple distributed database systems, the technology is highly secure by design.
The most important peculiarity of the Blockchain technology is its immutability, this means that the information remains in the same state ad perpetuam.