My Way of Explaining What "A Cryptocurrency" Is To People Who Don't Get It

Hi Everyone!

            Yesterday I walked into my local coffee shop where my roommate works. I got him into trading a month or two ago and he was attempting to tell his coworker what cyrptocurrency is but she couldn't wrap her head around the fact that it is not physical.   
            So I went with this: So imagine that your debit account is like a cryptocurrency. You put funds in it that you can not physically touch but you know the value is there and never question that you have that money. Now take that debit account and put it on a stock exchange so the value can increase or decrease depending on factors that affect the market. Now you have money (that you don't doubt you have) fluctuating over time and (hopefully) increasing which you can then withdraw into fiat. 
             Then BOOM she got it! I wanted to get everyone's opinion on how they go about informing people when you are questioned! 

Thanks For The Support!