what is Bitcoin ??

It's hard to deny that Bitcoin is changing the way we use money, and our concept of how currency should work. 
So what is Bitcoin exactly



Bitcoin is a form of digital currency, created and held electronically. No one controls it. Bitcoins aren’t printed, like dollars or euros – they’re produced by people, and increasingly businesses, running computers all around the world, using software that solves mathematical problems.

It’s the first example of a growing category of money known as cryptocurrency.