What is the difference between a public and a private blockchain?

A public blockchain is a decentralized and open network where anyone can participate, validate transactions, and access the ledger. Bitcoin and Ethereum are examples of public blockchains, where users can freely join the network, mine, and verify transactions. On the other hand, a private blockchain is restricted to a specific group of participants, typically managed by an organization or consortium. In a private blockchain, only authorized entities can validate transactions and access the ledger, offering greater privacy and control. While public blockchains prioritize decentralization and transparency, private blockchains are often preferred by businesses for their efficiency, privacy, and security.