Ethereum is the main platform of today’s blockchain world. Ethereum is the operating system. Ethereum is the canvas, the paper, or that bar bathroom wall that you can’t help but read. It is the protocol people build upon. Ethereum is a generalized blockchain; it’s not specialized for any one purpose (unlike Bitcoin’s). It is generalized so that anyone can program it for their specific needs. Almost all ICOs hosted in ETH platform, we won't see that many altcoins in the market if there's no ETH