Blockchain is a system of recording information in a way that makes it difficult or impossible to change, hack, or cheat the system. A blockchain is essentially a digital ledger of transactions that is duplicated and distributed across the entire network of computer systems on the blockchain.The purpose of the blockchain is to share information amongst all parties that access it via an application. Access to this ledger in terms of reading and writing may be unrestricted (‘permissionless’), or restricted (‘permissioned’).
Blockchain can be defined as a chain of blocks that contains information. The technique is intended to timestamp digital documents so that it’s not possible to backdate them or temper them. The purpose of blockchain is to solve the double records problem without the need for a central server.
The blockchain is used for the secure transfer of items like money, property, contracts, etc, without requiring a third-party intermediary like a bank or government. Once data is recorded inside a blockchain, it is very difficult to change it.
The blockchain is a software protocol (like SMTP is for email). However, Blockchains could not be run without the Internet. It is also called meta-technology as it affects other technologies. It is comprised of several pieces: a database, software application, some connected computers, etc.
Sometimes the term is used for Bitcoin Blockchain or The Ethereum Blockchain and sometimes, it’s other virtual currencies or digital tokens. However, most of them are talking about distributed ledgers.
