What is "A bitcoin"?
Seems to me to be the biggest confusion i run across when trying to explain bitcoin to people.
Sites in plenty explain what "bitcoin" is but that leaves some people still confused.
Some of the confusion comes from thinking there are "coins".
There aren't any really - there are no "coins" in bitcoin.
I explain it like this
"A bitcoin is (at the time of writing) 1/25th the reward paid for confirming the validity of a block of bitcoin transactions"
Not so long ago it was 1/50th the reward.
In the not too distant future it will be 10/1250th the reward. It will get smaller until there are only rewards from transaction fees.
At any point in time there is also an exchange rate such that you could say:
"1 bitcoin is USD$150"
but there are still no bitcoins so to speak.
The decimal point in a bitcoin balance is in a way quite arbitrary. It set a starting point for an exchange rate.
bitcoin - whoever Satoshi Nakamoto is he/she/them and Adam Black should get a Nobel Prize for something absolutely stunning in it's brilliance - but otherwise i'm sure he/she/they are entitled to The Well Deserved Fortune of Satoshi Nakamoto, Bitcoin creator, Visionary and Genius.
Buy with bitcoin? Sure you can!