Good day everyone. Am glad to be a part of the season three of the Crypto academy. Thank you professor @sapwood for the lectures. This is my submission post for the home work; task 4: question 1.

TITLE OF HOMEWORK: TASK 4 ; QUESTION 1

WHAT IS THE DIFFERENCE BETWEEN PoW & PoS? || ADVANTAGES & DISADVANTAGES? || WHICH ONE IS BETTER IN SCALING CAPACITY? EXAMPLES?

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WHAT IS THE DIFFERENCE BETWEEN PoW & PoS?

PoW means Proof of work while PoS is Proof of stake.
Proof of work is a consensus mechanism that requires very large quantity of energy for the computing powers used by the miners while proof of stake is based on how much cryptocurrency a validator owns and puts at stake. The more the validator stakes, the more efficient their mining ability.
Proof of work is based on mathematical equations which the miners competes to solve using cryptograph. These mathematical quations are difficult and only very powerful computers can solve them, therefore it consumes large amounts of electricity and only produces limited number of transaction per time. Proof of stake does not require the validators to solve mathematical equations but they are selected to validate a percentage of their transactions equivalent to their stake of ownership in the network.
Proof of work does not have high scalability while proof of stake has high scalability. Proof is work depends on miners while Proof of stake are upheld by validators.

ADVANTAGES OF PROOF OF WORK

• Proof of work consensus mechanism makes the blockchain network very hard and expensive to attack.
• Proof of work gives the miners both a share of the transaction fees and a block reward as rewards.
• Proof of work consensus mechanism gives rise to a more decentralized network

DISADVANTAGES OF PROOF OF WORK

• Proof of work consumes much energy, therefore it's expensive to run
• Much of the computational power required in proof of work is lost whenever an equation is solved
• Proof of work over time discourages mining as newly minted tokens near the cap

ADVANTAGES OF PROOF OF STAKE

• Proof of stake does not consume much energy because it does not require computational power as in the case of proof of work.
• Proof of stake has better rewards for the validators that stake their Cryptocurrency.

DISADVANTAGES OF PROOF OF STAKE

• Proof of stake gives rise to a less decentralized network
• Proof of stake is less secure and is more prone to low-cost attacks

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WHICH ONE IS BETTER IN SCALING CAPACITY? EXAMPLES

Proof of stake is better in scaling capacity; it requires less transaction time and does need computational power to mine.

Examples of proof of stake users are;
Dash
NEO
NOW
Tezos
Flow token
PIVX: Private instant verified transactions
Neblio
QTUM
NAV Coin
Stratus etc

Conclusion:

Thank you once more professor@sapwood for this lecture. I've known that there are different types of consensus mechanism which includes Proof of work, proof of stake, proof of capacity, delegated proof of stake and etc. The most commonly used consensus mechanism by popular blockchain like bitcoin, litecoin is proof of work. Proof is work required very large amount of electricity for it's computational work but it results to a more decentralized system.