Proof of Authority is a consensus mechanism where members of a cryptocurrency network are identified and receive delegated powers to solve blocks.
If they defraud the system their identity is at stake and they will either be prosecuted or booted from the network.
This is a centralized system where a higher authority delegates mining powers to trusted parties.
This system cannot work among anonymous parties and requires identification and trust in a group of people.
PoA is also more environmentally friendly than PoW as it does not use large amounts of energy during its operation.
POA Network uses PoA implemented in the Ethereum blockchain.
Return to main article: ELI5 Summary of cryptocurrency consensus mechanisms