bitcoin is the first currency.Blockchain is the technology behind Bitcoin.It's hard to imagine that the world of cryptocurrency exists without Bitcoin but this can happen in the world of crypto.people who have a lot of money because they use it as a form of assets to hide their wealth in the form of bitcoin . Some people use it as a form of payment inside or outside the country and anyone who allows or accepts bitcoin as payment. I think that's a lot more than usage and that's why bitcoin is number one in the market today.