Lesson 1: Understand the different types of blockchains

Are there different types of blockchains?

In fact, there are three main types of blockchains: public, private, and consortium, in addition to project-specific classifications such as "Bitcoin blockchain" and "Ethereum blockchain".

These can be classified in terms of whether or not the total number of nodes that make up the blockchain can be ascertained, and whether the number of administrators is plural or singular.

Let's take a look at the characteristics of each and some examples of typical blockchains.

Overview of public chains

A public blockchain is called a "public chain," and most blockchains fall into this category.

Therefore, most discussions are based on the assumption that "blockchain = public chain".

The blockchains we will learn in PoL will also be based on this assumption.

Since public chains are managed by countless miners, there is no specific company or other operator, and all recorded data is open to the public, so they are literally decentralized.

Typical examples of public chains are Bitcoin and Ethereum.

Overview of private chains

The counterpart to the public chain is the private blockchain.

This is called a "private chain," and it has a specific operator, can edit and delete the recorded data, and is private.

For this reason, some people believe that a private chain is not a blockchain but just a database. (We will learn more about this in Lesson 4.

Overview of consortium chains

A consortium blockchain is called a "consortium chain," and its image is somewhere between a public chain and a private chain.

A consortium blockchain is a blockchain that is managed by a number of identifiable operators, and data is available only to those operators.

Public chains are concerned about privacy issues because all data is public, while private chains cannot fully utilize the characteristics of blockchain.

In these situations, consortium chains are the best choice.

Therefore, consortium chains are often formed by companies in the same industry.

Typical examples of consortium chains are the "Liquid Network," which is led by Blockstream and involves about 20 exchanges, and "Hyperledger," which is led by the Linux Foundation and involves more than 30 IT companies.