Bitcoin is the main coin in cryptocurrency, why do I say it is the main coin? The answer is because Bitcoin is the first Crypto coin born, And now Bitcoin has become the King of Cryptocurrency with the highest price and the highest market capitalization volume. If we are now unable to buy Bitcoin, then we can buy Alternative Coins (Altcoins) which have a cheaper price but have the same function. Between Bitcoin and Altcoin, it can be used as a digital currency, invested also traded.