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This is a repost of my homework task 6 for prof @sapwood which has been graded but not upvoted till the post payout. Below is the screenshot of the grade by @dilchamo

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Here is my homework post for beginners task 6 by professor @sapwood with the question: 

> **What is the difference between PoW & PoS? Advantages & Disadvantages? Which one is better in scaling Capacity? Examples?**

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# <div class="phishy"><center>Definitions</center></div>
 ### What is PoW?

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![w1D7k7uj.png](https://cdn.steemitimages.com/DQmQr8ss2fB1CfNb2WHdrs4zyF3mT42BKkWRRAsoiQTqB9p/w1D7k7uj.png)<sub>[source](https://write.as/doctor-change/the-environmental-impact-of-proof-of-work)</sub>
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PoW means proof of work which is one of the mechanism a  blockchain technology of Cryptocurrency uses in verification of transaction. The verification of the transaction is been made by personnel who works the problem of the hash algorithm to decrypt the transaction details and there by approving them by addIng them to the block chain. These personnel are been referred to as the miner. 


The process of verification need the miner to work which is the major reason behind the name proof of work. The miner complete to Solve the hash as the quickly is been rewarded for completion of the work done by the blockchain. Mining is the process in whih miner of the network compete  to get the workdone. 
 
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### what is PoS?

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![proof-of-stake.png](https://cdn.steemitimages.com/DQmZZhhZFnL31PYfmZjtPJtxuq3xwSAGbaLRMqWWdDE7Kpc/proof-of-stake.png)<sub>[source](https://crypviz.io/en/knowledge-database/proof-of-stake/)</sub>
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PoS means proof of stake which is another mechanism for verification of transaction on the blockchain network of Cryptocurrency. Staking of a particular amount of  the blockchain currency gives the opportunity to become a validator of transaction and if not a validator, an attester who bear witness of  the validator before the verification of transaction and  a block been minted. 

The stake is the amount of coin in a wallet connected to the blockchain which give a block validator right to mint new block, proportional to the amount of his stake on the blockchain. Hereby giving to larger stalker a edge on the blockchain over other. 




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# <div class="phishy"><center>What is the difference between PoW & PoS?</center></div>
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![images (9).jpeg](https://cdn.steemitimages.com/DQmSb3HAMXmhENnwoB5eYmLLtP8fum2PeikkugR5BPMSX8p/images%20(9).jpeg)<sub>[source](https://edge.app/blog/proof-of-work-vs-proof-of-stake/)</sub></center>

PoW and PoS are quite similar as they are both used for the same purpose but the end result are been achieved in different ways. This gives rise for the question about the difference between these two consensus mechanism. The table below compare some fact stating the difference between proof of work and proof of stake. 
proof of work (PoW)|proof of stake (PoS)
---------------|---------------
PoW make use of the miner and the mining process for the verification of transaction on the network. | PoS uses the ownership of coin to choose validator and attester for the verification.
PoW gives reward to miner in form of new coin for every successful mining | PoS do not give this kind of reward as only the validatoin fee is received by the validator.
PoW Mining process lead to the increase in supply of the coin on the blockchain as the mining reward are given in new coin. | PoS does not increase the supply of the coin as the procedure for verification is different
PoW depends on the hardware and work done by the miner to give result | PoS depends solely on the amount of stake the validator has made 
PoW are limited in scale and they are not as fast as the PoS mechanism| Pos are faster in verification of transaction and they are more scalable. 
PoW consumption of energy is very high has the work done in the mining process requires a lot of energy usage| Pos energy consumption is minimal as it work with staking of coin 
PoW  also allow decentralised in it's full form as the mining process can not be done a node| staker with the highest number of coin has the most advanctage on Pos which reduces Decentralisation of the power 
PoW security is ensured by the high cost of hardware and mining resources| pos security is ensured by the impossible not one user to own or stalk more than half of the coin in the blockchain.


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## <div class="phishy"><center>Advantages & Disadvantages?</center></div>

### Advantages of PoW
* PoW gives block reward  to miners for successful verification of transaction  Which serve as a payment for effort made toward the blockchain.
* PoW depends on the knowledge of solving the algorithm and expensive hardware which discourages hacker leading to security of the system
* PoW gives room for verification of transaction without identification of the personnel involved in the transaction 


### Disadvantages of PoW
* The high cost of mining hardware and it's management make smaller minier to stop mining and everybody going to the lager group of miners leading to centralisation.
* Energy consumption by the mining process is a problem for the environment as it competefor resources  needed by the environment.
* The block reward are new coin which increases the supply of the coins in the blockchain
* PoW cause high transaction fee if  they are load of pending transaction awaiting verification 
### Advantages of PoS
* PoS make use of lower energy compared to PoW as it do not make use of the mining process for verification of transaction which make its environmental impart minimal
* PoS transaction are fast and yet still they offer a stable mechanism which I return make transaction faster

*  Pos do not make use of hardware which are termed to be expensive  hereby reduces cost when compared to PoW

### Disadvantages of PoS
* PoS works with the stalking of coin which gives user with the larger stake the higher advantage on the blockchain hereby give room for centerlization in the blockchain

* The reward for the proof of stake is low as that is not reward for validation of transaction apart from the transaction fee which in most cases are small. 

* It's is impossible to stake and sell your coin and even staking has a period of time in which you cannot withdraw from  until this period Is over. 

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### <div class="phishy"><center>Which one is better in scaling Capacity? Examples ?</center></div>

Scaling is the ability of the mechanism to increase the number of transaction it's can verify per minute. This allow a block to take in more transaction If the number of transactions increase. 

After reviewing the definition, differences, advantage and disadvantage of both the proof of work and the proof of stake, we see point that back the fact that the proof of stake is better in scaling as it has mechanism which give room for flexibility of the time and speed of transaction. Therefore the **proof of stake** is better with scaling capacity.  

#### Example of PoS
Some cryptocurrency adopt the proof of stake instead of the PoW used by even the first Cryptocurrency bitcoins while some are even moving to the PoS from the PoW e.g etherum. Below are examples of Cryptocurrency that make use of the PoS 
* Cardano
Cardano maske use of the proof of stake to run its own blockchain system with it's token *Ada*. The token was created with the intention to overcome issue bitcoin and some other coin are facing from using the proof of work mainly the scalability of the network. Cardona as the highest market cap of any token using the proof of stake before etherum adopts these same mechanism

* Algorand
Algorand used the pure proof of stake giving their own influence on the decentralized of the block chain for security  fast and removal of bad  processing .   It has  the second highest market cap for token  using the proof of stake on Thier blockchain

* Others include:  tezo, Mina, NEO, bitshare etc.

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# <div class="phishy"><center>Conclusion</center></div>

 The proof of work and the proof of stake has given blockchain technology it's ability to achieve most of it's qualities that make Cryptocurrency stand out to our local currency. The proof of work has proven to be good but the issue of energy consumption has been a thought of concern which is making newer blockchain  give the proof of stake room as their consensus mechanism.