It is hard to get your head around how bitcoin works. One of the pithiest explanations I have come across is in a recent launch by Ethereum, a business built to follow up on bitcoin: ‘The innovation provided by Satoshi is the idea of combining a very simple decentralised consensus protocol, based on nodes combining transactions into a “block” every ten minutes, creating an ever-growing blockchain, with proof of work as a mechanism through which nodes gain the right to participate in the system.’
