If you haven't heard by now, Bitcoin is up more than 1,500% this year. You're asking, what is Bitcoin? Basically it's a digital currency, kind of like an alternative to the dollar or euro.
Bitcoin, Ethereum, Bitcoin Cash, Ripple, IOTA, Litecoin, Dash: Price ...
Cointelegraph (Bitcoin, Cryptocurrency and Blockchain News)
Ripple Up More Than 90% In Last 24 Hours