Bitcoin is difficult to explain. I also felt difficulties in understanding bitcoin for the firs time. Let's share how to explain bitcoin to children of teenagers. In My country I can say 98% children don't know bitcoin. In fact, bitcoin can be future money. If the children not familiar with cryptocurrency or bitcoin, how can they face the digital era in the future.
Teenagers can not afford a Bitcoin anymore; them days are long gone.
Really they will not be able to buy bitcoin but the good thing is they can know about bitcoin more important than having. someday will make them excited and have bitcoin so introducing bitcoin is more important.