> What's the theory behind them? There is no theory, each one is different. Some propose different ways to do transactions, or different scaling solutions, dif

> What's the theory behind them? There is no theory, each one is different. Some propose different ways to do transactions, or different scaling solutions, different governance, different ways to do smart contracts etc. Some are poor solutions, others are outright scams. BTC and ETH aren't special, they're just big. BTC has the market place it has because it was first, not because it's better in any technical way. Similarly with ETH - it has a large community but it isn't necessarily better at smart contracts (or it might be - people will argue about this indefinitely).