In PoA-based networks, transactions and blocks are validated by approved/authorized Nodes, known as validators. How specific validator nodes are selected to create new blocks varies in different solutions, usually favoring some procedure randomize it.
The process is automated, extremely scalable and does not require validators to be constantly expending resources. It, however, does require maintaining the computer (the authority node) uncompromised, which usually means strict restrictions on who and how can operate a validator node.
Operating validator nodes typically earns incentive rewards, so there is an incentive to retain that position. Further, it is possible to attach a reputation to validators based on their performance and "honesty" ("node produces valid blocks") are incentivized to uphold the transaction process, as they do not wish to have their identities attached to a negative reputation.
This is considered more robust than PoS, as the amount of tokens staked or held has no influence on the nodes or their value/reputation to the network.
PoW uses an enormous amount of computing power, which, in itself lowers incentive
The three main conditions that must be fulfilled for a validator to be established are: 1. Identity must be formally verified on-chain, with a possibility to cross-check the information in a publicly available domain 2. Eligibility must be difficult to obtain, to make the right to validate the blocks earned and valued. (Example: potential validators are required to obtain public notary license) 3. There must be complete uniformity in the checks and procedures for establishing an authority
High throughput; scalable
No mining mechanism like in PoW, PoA uses identity as the sole verification of the authority to validate,
PoA is suited for both private networks and public networks
PoA only allows non-consecutive block approval from any one validator, meaning that the risk of serious damage is minimized.
By identifying validators it is a centralized system