Blockchains fall into three categories ： The chain of public 、 League chain 、 The chain of private .
The public chain is completely open , Rely on encryption technology to ensure security . Public blockchain is the earliest blockchain in the world , It is also the most widely used blockchain .
Alliance chain is a group of internal designated multiple preselected nodes as bookkeepers , The generation of each block is determined by all bookkeepers , Other nodes （ member ） Can participate in the transaction , But you can't access the data , Unless you've been granted permission .
Private chain data is not public , Users can access data or change data , The data of public blockchain cannot be modified .
Blockchain is accompanied by the emergence of digital currency , The original application scope of blockchain was entirely on digital currency . As the market for digital money grows bigger , Affected by this , People began to extend the application scope of blockchain to the financial field . Blockchain continues to grow , The characteristics of decentralization in other areas also began to receive attention , Blockchain is also applied to domain names 、 logistics 、 In medical and other fields , Its application scope is gradually expanding .