As anyone who doesn't have a degree in advanced computer science knows, Bitcoin is conceptually tricky. Thus, when your grandmother is wanting to buy marijuana off the Silk Road and begins asking you to explain Bitcoin to her, what do you do? Ever since early 2012, when I asked the question 'what the hell is Bitcoin?', I've been trying to find ways to explain it to myself. Initially I used the example of the Borg from Star Trek, but more recently I've come to believe that one key to describing it is to start from normal currency, and to then describe Bitcoin in relation to that, rather than trying to describe it as a standalone phenomenon. I'm no Bitcoin expert, so this is still a work-in-progress (Warning!), but next time granny asks you, here's a rough-and-ready way you might lay down the foundations (I've deliberately included a lot of repetition, because that's important when learning).
1) Start from physical cashWe all have a basic understanding of physical bank notes. We know that we can store a banknote in our wallet, and then exchange it directly with someone else for goods or services. We can do this because we collectively believe the note to have value, anchored as it is within an immensely powerful cultural system which gives it such value, and further reinforced by our belief in the central banks that issue it, and the governments that accept it for tax.
2) Now contrast physical cash with electronic bank moneyMost of our transactions though, are with electronic money. That's the money you see when you log into your online banking account, and that you can use to make electronic payments (if you granny doesn't do internet banking, talk about the numbers on the ATM screen). Where is that electronic money stored? It's not like I have a wallet that has electronic cash in it that I can take out and give to someone. All our electronic money is actually stored in the IT systems of commercial banks.
3) Point out that electronic money is just a number in a bank's computer, attached to your account ID
DATACENTRE: WHERE YOUR E-MONEY IS STOREDTo 'store' your electronic money, all the bank really does is maintain an internal ledger, which is a list that says "Brett has deposited X amount into the bank, and he has received X amount in payments, and he has withdrawn X amount from ATMs, and has paid X amount to other people via electronic payments, and this is how much he has left." And that's the amount you see on your bank statement. Your current bank balance is thus the product of a series of transactions over time that the bank validates and records.
4) Then point out that I cannot hold this electronic money in my own computerIf I had to call Co-Operative Bank up and say, "I have £350 in my account with you. It's currently in electronic form. I'd like to take it out of the bank. Please can you transfer it to me in electronic form, so that I can store it directly on my computer", they'd laugh at me. They'd just say "Sorry Mr. Scott, it's just numbers recorded next to your account ID. We can convert it into cash and give that to you if you come into a branch, but we cannot give it to you in electronic form, unless you could specify another bank where you have another account." - Read more here: http://suitpossum.blogspot.co.uk/2013/04/how-to-explain-bitcoin-to-your.html