What is public chain in blockchain
blockchain includes public blockchain, joint (instry) blockchain and private blockchain. Public chain point-to-point e-cash system: bitcoin, smart contract and decentralized application platform: Ethereum
blockchain is a new application mode of distributed data storage, point-to-point transmission, consensus mechanism, encryption algorithm and other computer technologies
blockchain is an important concept of bitcoin. In essence, it is a decentralized database. At the same time, as the underlying technology of bitcoin, it is a series of data blocks generated by using cryptographic methods. Each data block contains a batch of bitcoin network transaction information, Used to verify the validity of its information (anti-counterfeiting) and generate the next block
extended data
according to the different degree of blockchain network centralization, three kinds of blockchains under different application scenarios are differentiated:
1. The blockchain with the whole network open and without user authorization mechanism is called public chain
2. The authorized nodes are allowed to join the network, and the information can be viewed according to the authority. It is often used in the inter agency blockchain, which is called alliance chain or instry chain
3. All the nodes in the network are in the hands of one organization, which is called private chain
alliance chain and private chain are also called licensing chain, and public chain is called non licensing chain
blockchain features
1, decentralization. Blockchain technology does not rely on additional third-party management institutions or hardware facilities, and there is no central control. In addition to the self-contained blockchain itself, each node realizes information self verification, transmission and management through distributed accounting and storage. Decentralization is the most prominent and essential feature of blockchain
2. Openness. Blockchain technology is based on open source. In addition to the private information of all parties involved in the transaction is encrypted, the data of blockchain is open to everyone. Anyone can query blockchain data and develop related applications through the open interface, so the information of the whole system is highly transparent
3. Independence. Based on consensus specifications and Protocols (similar to various mathematical algorithms such as hash algorithm used by bitcoin), the whole blockchain system does not rely on other third parties, and all nodes can automatically and safely verify and exchange data in the system without any human intervention
4. Safety. As long as 51% of all data nodes cannot be controlled, the network data cannot be arbitrarily manipulated and modified, which makes the blockchain itself relatively safe and avoids subjective and artificial data changes
5. Anonymity. Unless there are legal requirements, technically speaking, the identity information of each block node does not need to be disclosed or verified, and the information can be transferred anonymously
This is two different concepts. According to different standards, blockchain can be classified into three categories:
& # 8195 8195; 1) According to the network scope of blockchain, it can be divided into public chain, private chain and alliance chain
8195; 2) According to the docking type of blockchain, it is divided into single chain, side chain and interconnection chain
8195; 3) According to the display environment of blockchain deployment, it can be divided into main chain and test chain
the main chain can be understood as a formal online and independent blockchain network, while the public chain refers to a blockchain that can be read by anyone, can send transactions and can be effectively confirmed by anyone, and can participate in its consensus process

Blockchain is strictly divided into three types: public chain, private chain and alliance chain. The core difference between these three types of blockchains is the degree of openness or decentralization of access rights. Generally speaking, the higher the degree of decentralization, trust and security, the lower the transaction efficiency
generally speaking, each type of blockchain has its own specific mode and value, which is better than others. As long as the demand is solved, the blockchain is valuable

the difference between blockchain and ordinary mall is that it adds the function of virtual currency. You can see the interface and docking method of virtual currency at other times to avoid mistakes
(1) running on the Internet
(2) completely distributed< (3) the number of data nodes is changeable and unpredictable< (4) the data is public< (5) anyone can participate anonymously
(6) the operation and maintenance cost is high and depends on the reward mechanism< (7) the transaction speed is slow.
