Bitcoin is the first and historians' main cryptocurrency, according to legend, created by Satoshi Nakamoto. The key features of Bitcoin are decentralization, anonymity, and security.
Bitcoin is considered a correlation instrument for other cryptocurrencies. If Bitcoin rises, it will push other cryptocurrencies to rise as well. Likewise, the value of altcoins decreases when BTC falls. In practice, scalpers observe bitcoin when trading any cryptocurrency.
The first 50 BTC were generated on January 3, 2009. Bitcoin issuance will cease around 2140, after 21 million tokens have been issued. At the moment, for one reason or another, about 28.5% of BTC of the fixed emission size has been lost.
Bitcoin is split into smaller pieces. So, 1 BTC = 100,000,000 Satoshi.