I've read through some explanations saying that every client in the network knows every transaction because when someone wants to perform a transaction, he sends that informationen (how much, to whom and his own address) to everybody he knows and everybody they know and every.... and so on. Until it gets confirmed by everybody in the network. Then the transaction can take place. So everybody in the network knows that this transaction happens, and add the new block to their chain.
Does REALLY everybody have the whole history of transactions (a.k.a one HUGE chain of blocks) stored on their (lets say) computer?
Really all? Isn't this amount of bytes too much for normal hard disks (in my computer, smartphone, ...) considering ALL transactions which have ever happened and happen?