Bitcoin is a popular cryptocurrency that was created in 2008 by an anonymous individual whose nickname is Satoshi Nakamoto
The main intent of the Bitcoin creator was to make it possible for people to send and receive payments across countries of the world without a third-party(banks) and at a very low cost.
BTC is also known as the ticker symbol for Bitcoin
Bitcoin is the market capitalization leader meaning that no other cryptocurrency can surpass the market cap of BTC
Further Reading