Open source public blockchains such as Bitcoin, Litecoin, and Ethereum are known for being accessible to all. Anybody can download the software that runs these projects and participate in many aspects of their respective networks and ecosystems. Additionally, all transactions are free and open for the entire world to see. This is in stark contrast to a Private Blockchain, a closed network controlled by a single centralized entity. To view, interact, or participate in any aspect of a private blockchain, you must be invited and authorized by the centralized authority or owners.
NFT Term
Private Blockchain
Definition of Private Blockchain from the NFTguild.com glossary.

