Bitcoin is a cryptocurrency, discovered in 2009 by Satoshi Nakamoto (anonymous to the public), and just like every cryptocurrency, does not require banks to undergo transactions. You can pay hotels on Expedia, shop for video games and buy furniture on Overstock. According to CNN Tech, the price of a bitcoin skyrocketed, costing thousands of dollars in 2017.
When Satoshi Nakamoto invented the blockchain in 2008 as the bitcoin’s public transaction ledger, bitcoin became the first digital currency to solve the double-spending problem not requiring a central authority or central server.
Picture resource: https://coinsutra.com/bitcoin-facts/