Thank you respected Professor @alphafx for the lesson and well supported by @levycore.
Below is my attempt for the Home Work Task:

I will like to explain the meaning of consensus algorithm before explaining further one of the types.

Consensus algorithm

Consensus algorithm is very important in every blockchain especially in decentralized blockchain network, it is responsible for the management and authentication of transaction so as to ensure transparency since there is no authority controlling the transactions.

Consensus algorithm is a procedure or protcol through which users or nodes of a blockchain program have an established agreement on a common truth in a decentralized system or process. It is a mechanism through which all users of the blockchain network like bitcoin, etc, come to consensus on the state of a ledger and there is reliability and security in the trading environment.

Consensus algorithm focus on building a reliable decentralized blockchain environment where users can operate without the fear or been cheated or scammed, agreement are entered into the system and transactions are included in the ledger only when verified and valid.

Source

Proof of capacity (poc)

Proof of capacity also known as proof of space is a consensus algorithm protocol used in blockchain networks that enables miners to use their free hard drive space to authenticate a transaction. Miners accept a challenge to find solutions to a mining problem and the solutions are computed and stored into the hard drive and they are reward with a block and coins applicable to their plots when the mining begins.

How proof of capacity works:

There are two important concept in proof of capacity and they are plotting and mining.

Plotting: simply means developing a unique plot files and by doing this, Plotting use shabal method in hashing, This hashing algorithm is complex to compute than the SHA 256 algorithm used in bitcoin pow. In using the shabal, a nonce is created and a miner is expected to hash continuously till the nounce is solved and also include is address or ID so the mine can be only one to use the plot files. Each plot file or nonces is made up of 8192 hashes ranging from 0 to 8191 and nonce are further divided into two that us 4096 hashes each but they are referred to as scoops and a unique number is assigned to each and the mining process start.

Mining: this is the last process in proof of capacity, after successful creating a plot files, miners makes research for current block by using the generation signature from the past block, the current block index and base target. After completing the research and all neccessary information have been gotten, the miner then develop a new generation hash is used to search for the scoop number among the nonce, it is usually between 0 to 4095 and this scoop number and ounce will be further used to calculate the deadline.Deadline is the total number of time since the past block was mined before the miner can mine the next one. Any miner with the smallest deadline is entitled to the forge.

The benefits of proof of capacity:

The proof of work algorithm is very eco-friendly, it uses the available space on your hard-drive instead of high energy consuming CPUs and GPUs.

Unlike proof of work that uses ASIC hard ware that is associated with high electricity consumption. POC is pocket friendly and doesn't increase electricity bill much as you just have to on your computer only.

Easily accessible, everyone can get access to mine on proof of capacity alogritum since there is low entry barrier which is just hard drive infact almost all household in the world own a computer now and you can use your computer to assess easily so far you have enough space on your hard drive.

There is no need to spend much money on GPU and ASIC cooling system and there is no need for constant upgrading of system or hard drive, you can even reuse your old hard drive by wiping off old data and using it to start new ones.

There are some draw drawbacks associated with the proof of capacity algorithm and they are:

Users are at risk of malware attack, when this system becomes more popular, hackers might try to exploit it and hack into the system to steal coins or install malware into people's device, the easy access system with no adequate security of users is one of the shortcomings.

The use of harddrive could make the early birds mine most coins, people can get higher hard drive to mine more coins and this will affect the decentralization of the network.

Also only few blockchain networks are using the algorithm, most developers are not in support of this system unlike the the proof of work alogritum which is used by alot of developers.

Two examples of cryptocurrency using the proof of capacity algorithm:

Burstcoin: Burstcoin also know BURST is a digital currency developed to have an eco- friendly mining, it was the first coin to use the proof of capacity protocol and it support smart contract functionality known as burst assest exchange and other characteristics associated to other virtual currency the only difference is how the coins is mined. BURST uses the proof of capacity process and some other cryptocurrency like bitcoin uses the proof of work process.

Burstcoin operates with a block time of 4 minutes and miners are paid through the native digital wallet known as burst wallet and a unit of burstcoin currently is $0.01189 with a market capitalization of $24 million.

Chia: chia is a new cryptocurrency that was introduced to the market early of this month, it is also an eco- friendly alternative to bitcoin, it also uses the proof of capacity algorithm but it is known as farming. The developers which is the chia network said their aim is to have a greener and highly energy efficient cryptocurrency that serve as alternative to bitcoin. The native currency used in this system is known as CHIA and a unit of CHIA is currently sold at $1010 and the market capitalization is $520 million.

Thank you for reading my post.

Cc: @steemcurator02