Basically, blockchain is a decentralized online accounting ledger that records all transactions of a particular network over a specified period of time. It is protected and encrypted for security. Blockchain was invented by Satoshi Nakamoto in 2008 after the world economic crisis. Unlike centralized database, blockchain is decentralized, making it hard to be attacked.
Not true, you can have a centralized blockchain, just run a single node. That is why blockchain alone is insufficient.
You would be surprised how many people abuse the word "blockchain" because it sounds trendy.
