What is Public Blockchain ?
A public blockchain is also known as Permissionless Blockchain. Anyone can join the Blockchain network and information is available in a public domain. Due to its permissionless nature, any party can view, read, and write data on the blockchain and such data is accessible to all.
No particular participant or a node in the network has full control over the data contained in a public blockchain. Bitcoin and Ethereum are good examples of Public Blockchain.