Public Blockchain

Because a public blockchain has no gatekeeper, its security and integrity depend entirely on decentralization: thousands of independently operated computers, called nodes, each hold a full copy of the ledger and check every new transaction against the same rules. Anyone can download the software, run a node, and verify the chain for themselves, which is why public networks are often described as trustless. Users don't need to trust a company or government, only the open-source code and the economic incentives that keep participants honest.

Bitcoin, the first public blockchain, still relies on Proof-of-Work mining to reach agreement on the state of the ledger. Ethereum switched from mining to Proof-of-Stake in 2022, letting validators who lock up ETH as collateral propose and confirm blocks instead. Solana, Litecoin, and most other major layer-1 networks follow the same open-membership model, though they differ in consensus design and throughput.

The trade-off for this openness is capacity and control. Public chains process transactions in full view of anyone, which limits privacy, and shared block space means fees rise when demand spikes. Enterprises that need confidentiality or predictable throughput often choose a private or permissioned chain instead, accepting a trusted operator in exchange for speed and access control. For applications that prize censorship resistance and verifiability over privacy, a public blockchain remains the standard choice.