Below is a comical take on how crypto-currency works.

And what about block chain technology that allows crypto-currency to exist? Here is a short answer: “The blockchain is an incorruptible digital ledger of economic transactions that can be programmed to record not just financial transactions but virtually everything of value.”
Don & Alex Tapscott, authors Block-chain Revolution (2016)

If you want to understand block chain you can go to

Bitcoin wow! Purchase for 25 cents and watch the value climb to $20,000 and then down to $10,000. Too many people bought into the hype when it was $15-20,000 and lost a lot of money.

It’s a great idea. Make up a currency, avoid banks and taxes. Well the governments are figuring out how to get their taxes and investment banks are jumping on the crypto-currency band wagon.

Here is a fun explanation: