What is PoW

Used by Bitcoin, Ethereum, and many other public blockchains, proof-of-work (PoW) was the very first consensus mechanism created. 

Ethereum is now heading to PoS consensus. Please refer to “What is Ethereum” for more information.

In PoW, miners essentially compete against one another to solve complex computational puzzles using computers. The first miner who solves the puzzle will be the validator of the new block and rewarded with a predetermined amount of coin, known as a “block reward”.

Who are miners? What is a validator? What do they mean to a blockchain? Please refer to “What is Mining” and “What is a Node / Validator”

PoW is generally regarded to be the most reliable and secure of all the consensus mechanisms, though concerns over scalability are common. 

However, in general, as it requires large amounts of computational resources and energy in order to generate new blocks, the operating costs behind PoW are notoriously high (such as the PoW mechanism in the Bitcoin ecosystem). This acts as a barrier of entry for new miners, leading to concerns about centralization and scalability limitations. 

Besides, the most common criticism of PoW is the impact electrical consumption has on the environment. This has led many to seek more sustainable, energy-efficient consensus protocols, such as proof-of-stake (PoS).

You might also be interested in the following content:

• What is a Block?
• What is Blockchain Trilemma?