Proof of Work a consensus mechanism behind bitcoin. It was introduced by Satoshi Nakamoto in 2008 in Bitcoin White Paper. The earlier example of Proof of Work is Adam Back’s HashCash before bitcoin created.
Proof of Work was an original solution of double spend problem. It is a reliable and secure mechanism that we don’t need for central authority to solve the problem. Cryptography (hash functions) used with computing power and algorithms to solve it.
Proof of work (PoW) describes a system that requires a not-insignificant but feasible amount of effort in order to deter frivolous or malicious uses of computing power, such as sending spam emails or launching denial of service attacks. The concept was subsequently adapted to securing digital money by Hal Finney in 2004 through the idea of “reusable proof of work” using the SHA-256 hashing algorithm.
Following its introduction in 2009, Bitcoin became the first widely adopted application of Finney’s PoW idea (Finney was also the recipient of the first bitcoin transaction). Proof of work forms the basis of many other cryptocurrencies as well, allowing for secure, decentralized consensus.(https://www.investopedia.com/terms/p/proof-work.asp)
- Proof of work (PoW) is a decentralized consensus mechanism that requires members of a network to expend effort solving an arbitrary mathematical puzzle to prevent anybody from gaming the system.
- Proof of work is used widely in cryptocurrency mining, for validating transactions and mining new tokens.
- Due to proof of work, Bitcoin and other cryptocurrency transactions can be processed peer-to-peer in a secure manner without the need for a trusted third party.
- Proof of work at scale requires huge amounts of energy, which only increases as more miners join the network.
- Proof of Stake (POS) was one of several novel consensus mechanisms created as an alternative to proof of work.(https://www.investopedia.com/terms/p/proof-work.asp)