Private vs. Public and Permissioned vs. Permission-less

http://blocktonite.com/2017/06/27/private-vs-public-and-permissioned-vs-permission-less/

the concept is that the public/private distinction has to do with user authentication (WHO are you) and the permissioned/permission-less distinction has to do with user authorization (WHAT can you do).

https://medium.com/@Francesco_AI/the-convergence-of-ai-and-blockchain-whats-the-deal-60c618e3accc

whether it is free for anyone to view it (permissionless vs permissioned) or to participate in the consensus formation (public vs private). In the former case, anyone can access and read or write data from the ledger, while in the latter one predetermined participants have the power to join the network (and of course only in the public permissionless case a reward structure for miners has been designed).