Blockchain, in essence, is a shared database, and thedata or information stored in it has the characteristics of"unforgeable", "full traces", "traceable","open and transparent" and "collective maintenance".
According to the degree of openness of the blockchainnetwork, it can generally be divided into three categories: public chain,alliance chain and private chain.
The public chain means that any individual or group in the world can send atransaction, and the transaction can be effectively confirmed by theblockchain, and anyone can participate in its consensus process. The publicchain is the earliest blockchain and the most widely used blockchain. Bitcoinis the most representative public chain.
Consortium chain means that multiple pre-selected nodes are designated asbookkeepers within a group, and the generation of each block is jointlydetermined by all pre-selected nodes (pre-selected nodes participate in theconsensus process), and other access nodes can participate in transactions, butHowever, if you ask about the bookkeeping process (essentially, it is stillmanaged bookkeeping, but it becomes distributed bookkeeping, how many nodes arepre-selected, and how to determine the bookkeeper of each block to become themain risk point of the blockchain), anyone else can The limited query iscarried out through the open API of the blockchain. At present, most of theblockchains between financial institutions such as banks are in the form ofalliance chains.
Private chain refers to: only use the general ledger technology of theblockchain for bookkeeping, which can be a company or an individual, and hasexclusive access to the blockchain. This chain is not much different from otherdistributed storage solutions. The difference is that the application productsof the private chain are still being explored.