Often I'm asked to explain BTC to someone and occasionally I come up with something stellar that really nails it, but most times it's a rambling incoherent mess.
What I would like to see is a short and simple explanation of what BTC is that is suitable for someone non-technical to understand.
You can explain, bitcoin is a virtual currency that can be a means of payment, but other than as a means of payment, bitcoin can also be used for investment because its value is increasing. I think it's easier to accept.