Every grouping of transactions is was a block and chained to the existing ledger. Once a block is included it cannot be reversed or altered — Which is the reason folks explain blockchains as "immutable." 区块链是一个交易数据库，在网络上多台电脑之间更新和共享。每次添加一组新交易时，就称其为“区块”，这也是区块链名称的由来。以太坊这样的公开区块链，允许任何人添加数据，但不能删除数据。如果... https://arthurvcegh.wikirecognition.com/869263/article_under_review