Proof of Work consensus mechanism simply means the show of work (proof) that has been done or put in. The more the work done, the more the reward is received.

In this mechanism, the data on the blockchain can be edited, maintained, added or deleted by a distributed ledger which is self-governing (thanks to decentralisation). In proof of work mechanism, anybody anonymous can join the network with any computer and become a validator.

Here, if a transaction is happening on the blockchain then everyone knows that it has happened and until and unless the work is proved, the transaction isn’t deemed complete. One block in the Bitcoin network can contain up to 100 transactions and miners execute proof of work to mine a new block.

On average a new block is added to the blockchain every 10 minutes and whenever a new block is added, the hash function syncs all the nodes to the same blockchain copy.

In simple words, this mechanism can be considered as a race that has been set up among many people. Whoever wins the race also ends up winning the reward, except here the race is between computers, the better the computing power the more are the chances of a person winning.Here, as a reward, the person gets awarded 6.5 Bitcoins for each block solved.

Furthermore, it also saves the blockchain from double spending, which is a way in which the number of coins is doubled or a transaction is entered twice resulting in the value of tokens getting reduced thereby becoming a major threat to the blockchain.

Since proof of work employs people validating transactions, a question can arise: what if a transaction is wrongly validated on purpose? Well, the beauty of the consensus mechanism is that it works on the majority, so to wrongly validate a transaction the person will require 51% of the total votes or the computational power on the blockchain. While it may sound less but in practicality, 51% of the votes would require the person to hold billions of validating computers which is logically impossible.

Furthermore, while solving a block, the password/solution to the block can only be guessed and whoever does that the fastest wins. This entire process merely takes seconds thereby leaving the intruder with very less time to make a false call. Hence, due to processes like these, the mechanism is Fair and happens transparently in real time while being efficient.

However, as good as proof of work might sound, it brings with it certain disadvantages.

1. Firstly, is its inability to scale.

2. high energy consumption.

Moreover, during peak times, the transaction fees can go extremely high and there are also no penalties imposed on people who commit fraud. These issues thus bring us to the Proof of Stake mechanism.