The definition of PoA is a consensus mechanism that entrusts selected groups or individuals to validate transactions and create new blocks in a blockchain network.

Proof of Authority is an advanced consensus mechanism aimed at companies or private organizations that wish to build their blockchain network, which is closed and does not require the involvement of the general public.

When compared to other consensus mechanisms, such as PoW (Proof of Work) and PoS (Proof of Stake), Proof of Authority (PoA) is a consensus mechanism that utilizes the identity value of a group of verified and trusted validator nodes.

This validator is also selected according to its authority or reputation on the network, unlike PoS, which looks at the economic aspect.

Therefore, PoA is more suitable for blockchain networks aiming to gain predetermined speed, scale, and trust. Further information regarding this topic can be found in the following article link.