Public blockchain networks often refer to permissionless networks that any user can participate in. Any individual in the world may choose to join the network, view, and/or transact on this network. This allows for high decentralization of public blockchain networks: they do not have a central authority that oversees the entire network and the transactions¹. As a result, no single user has complete control over the network and network’s data. Furthermore, they usually support anonymity: participants’ transactions, data, and general activity cannot be traced back to them. 

Even though no one can connect a user’s real identity to their network activity, all transactions are public within this type of blockchain². Therefore, as there is no administrator that can restrict access to the blockchain data, it is very challenging to achieve data privacy on this type of network. It is possible to set up a permissioned public blockchain too. The difference with public permissionless network is that not all the users can join the blockchain network and submit the transactions, yet everyone can access the data from the blockchain.

Private blockchain networks are permissioned blockchains that require users to have an invitation to join them. Governance in private networks is centralized, which means they do have an entity that regulates network activity and access to the data on the blockchain (unlike public blockchains). Transactions can only be submitted and seen by the users within the private network, and because there are a limited number of participants viewing said transactions, the network ensures privacy of the data and remains more stable than a public blockchain³.  

Consortium blockchain networks are somewhat similar to private networks. They differ, however, because the network governance is decentralized: a group, or consortium (hence the name), of entities manage the network instead of one enterprise like in private networks⁵. This is best for organizations that want to use the blockchain for enterprise activity. These networks can be harder to set up and govern, as multiple groups need to be organized and assigned access controls across the network. Consortium blockchain networks ensure a higher level of privacy and tend to be more efficient than public networks⁶.