Blockchain is a decentralized database that stores data in blocks. It is an immutable and transparent ledger that can be used to store anything of value, such as money, property or shares.

The blockchain network consists of computers that are all connected to one another. These computers are called nodes. Every node on the network has a copy of the blockchain, which they receive from other nodes. Whenever there's a new transaction, it is broadcasted to every node on the blockchain network for validation and verification.

This process ensures that transactions are recorded accurately and in chronological order without any chance of fraud or censorship because no single entity controls the data on the blockchain. Also you can read this article:https://www.denoffentlige.dk/erhvervsliv/hvad-er-blockchain-og-hvordan-fungerer-det