All we know is just about cryptocurrency use case of blockchain which is on public blockchain and many of the blockchain types are hidden which I am going to cover in this article.
Mainly there are two types of blockchains , public and private. As the names suggests public blockchains are open to all for exploration and participating whereas private blockchains are limited to some people or organizations so you can't just wake up and explore or participate in this type of blockchain.
However, there are several variations too, like Consortium and Hybrid blockchains. Now let’s have a look in detail about the four types of blockchains that are possible.
Public Blockchain :
A public blockchain is a non-restrictive, permission-less distributed ledger system. Just like ethereum and bitcoin. Any user who has access to internet can see all the data written on smart contracts and transactions details. here you can check -
etherscan provides all the details of transactions happened on ethereum blockchain. bitcoin is also on public blockchain. At the other hand you don't need to get any permission from anyone to join the network of ethereum. You can take part in POW or become a node in ethereum all with your will. The most basic use of public blockchains is for mining and exchanging cryptocurrencies. Thus, the most common public blockchains are Bitcoin and Litecoin blockchains. Public blockchains are mostly secure if the users strictly follow security rules and methods. However, it is only risky when the participants don’t follow the security protocols sincerely.
Private Blockchain :
A private blockchain is a restrictive or permission blockchain operative only in a closed network. these type of blockchains are used in perticular orgnization or enterprises where only selected members are participants in network.
Voting, supply chain management, digital identity, asset ownership, etc. are some use cases of private blockchains Examples of private blockchains are; Multichain and Hyperledger projects (Fabric, Sawtooth), Corda, etc.
Consortium Blockchain :
A consortium blockchain is a semi-decentralized type where more than one organization manages a blockchain network. This is contrary to what we saw in a private blockchain, which is managed by only a single organization. More than one organization can act as a node in this type of blockchain and exchange information or do mining. Consortium blockchains are typically used by banks, government organizations, etc.
Examples of consortium blockchain are; Energy Web Foundation, R3, etc.
Hybrid Blockchain :
A hybrid blockchain is a combination of the private and public blockchain. It uses the features of both types of blockchains that is one can have a private permission-based system as well as a public permission-less system. With such a hybrid network, users can control who gets access to which data stored in the blockchain. Only a selected section of data or records from the blockchain can be allowed to go public keeping the rest as confidential in the private network. The hybrid system of blockchain is flexible so that users can easily join a private blockchain with multiple public blockchains. A transaction in a private network of a hybrid blockchain is usually verified within that network. But users can also release it in the public blockchain to get verified. The public blockchains increase the hashing and involve more nodes for verification. This enhances the security and transparency of the blockchain network.
Example of a hybrid blockchain is Dragonchain.
There are some advantages for private blockchains such as speed and scalibility while disadvantages are trust, lower security, centralization.
At the other hand public blockchain offers more trust , security and more open and transparent but has lower transactions speed, scalibility and higher energy consumption.
So which one is better ? Well it depends completely on use case and where do you want to implement this technology. Thank you.