Public Blockchain Definition: A public blockchain refers to a platform with no restrictions. It’s also readily accessible; anyone with an online connection can access the network to send transactions and validate blocks. Users who choose to validate blocks on a public network are often offered incentives through a PoS or PoW consensus.
This type of blockchain is also known as a decentralized ledger, as it is easily accessible and not controlled by a single entity or authority. This model for cryptocurrency was initially designed by Satoshi Nakamoto in 2009.