Each individual grouping of transactions is changed into a block and chained to the existing ledger. After a block is added it can't be reversed or altered — which is why folks explain blockchains as "immutable." 以太币是以太坊的原生货币。要使用以太坊应用，你需要在钱包中预留一些以太币。 The lack of the central authority may also make cryptocurrencies safer. "It is https://ethbase37227.daneblogger.com/28357642/new-step-by-step-map-for-bitcoin-and-ethereum