So, what the heck is Blockchain?

"[Blockchain] is to Bitcoin, what the internet is to email."

- Sally Davies, Financial Times

"To understand [...] blockchain systems, and the things they can do, it is important to distinguish between three things that are commonly muddled up, namely the bitcoin currency, the specific blockchain that underpins it and the idea of blockchains in general."

- The Trust Machine, The Economist, Oct. 31, 2015

Blockchain: "[...] permits transactions to be gathered into blocks and recorded; cryptographically chains blocks in chronological order; and allows the resulting ledger to be accessed by different servers."

- Nancy Liao, Yale University, 2015