Public vs Private Blockchains: what's the difference?
You learned what is blockchain and that blockchain is not Bitcoin. The next step is to understand the difference between private and public blockchains.
The infographic below illustrates and simplifies the two concepts, highlights what they have in common and how they differ one from another.
In summary:
In the public blockchains, such as the bitcoin blockchain, there is no central individual or organisation with the authority or ability to make claims of control or ownership. Anyone can join a public blockchain and become part of the consensus. No single individual or organisation is responsible for it.
Private blockchains use the same technology principles, however they are individually or corporately designed and operated. Permissions are required to join the network. This can include being ‘invite only’. The protocol or operating system of a private blockchain can be amended by the operator.