What is Blockchain?
At its core, a blockchain is a distributed database or ledger that is shared among the nodes of a computer network. As a database, a blockchain stores information electronically in digital format.
Blocks and Chains
Blockchains collect information together in groups, known as blocks, that hold sets of information. Blocks have certain storage capacities and, when filled, are closed and linked to the previously filled block, forming a chain of data known as the blockchain.
Decentralization
Imagine a company that owns a server farm with 10,000 computers used to maintain a database holding all of its client's account information. This company has a warehouse containing all of these computers under one roof and has full control of each of these computers and all the information contained within them. This provides a single point of failure. Blockchain eliminates this by distributing the data across thousands of computers worldwide.