Who created it?
A pseudonymous software developer going by the name of Satoshi Nakamoto proposed bitcoin in 2008, as an electronic payment system based on mathematical proof. The idea was to produce a means of exchange, independent of any central authority, that could be transferred electronically in a secure, verifiable and immutable way.
To this day, no-one knows who Satoshi Nakamoto really is.
In what ways is it different from traditional currencies?
Bitcoin can be used to pay for things electronically, if both parties are willing. In that sense, it’s like conventional dollars, euros, or yen, which are also traded digitally.
But it differs from fiat digital currencies in several important ways:
