In this infographic, you can see a summary of blockchain technology with answers to: what, why, how, who, and where. It is based on HBR video: “How Does Blockchain Work?” by Karim Lakhani, released on 2017.
A blockchain is "an open, distributed ledger that can record transactions between two parties efficiently and in a verifiable and permanent way. The ledger itself can also be programmed to trigger transactions automatically." - The Truth About Blockchain (HBR, 2017)