A hard fork is an update that changes the protocol in a way that previously invalid blocks become valid. A hard fork will happen, but if 100% update we would avoid a split in the chain. I assume you switched the terms. Anyway great work. 
Edit: If 0% update, then you would avoid the hard fork/update.
I hope all of this makes sense.
Its on my list. It is my intention to complete every course on this site to be fair. Im really enjoying it so far. Bit daunting how much ive got here but I seem pretty good at cramming in lots of subjects these days. Cheers dude
A softfork is an update that contracts the rule set, making previously valid blocks invalid. A hardfork is an update that expands the rule set. making previously invalid blocks valid. Also, a hardfork will split the original blockchain into 2 chains. A softfork does not do that.
A hardfork can happen if a community votes to have a new currency because they want to update the rule set of the protocol.
One of the risks when performing a hardfork would be the split in the community. The community of the two chains will be smaller than before.
A hard fork update is an expansion of the rule set where previously invalid blocks are now valid whereas a soft fork is a contraction of the rule set where where previously valid blocks are now invalid.
It is the most democratic way of dealing with a fundamental difference in opinion within the mining community over a proposed change to the network, such as increasing the blocksize.
Network security will be reduced due to the reduction of hashpower resulting from being split into two chains.
I am glad to hear that you are enjoying the course, and that you are interested in taking all of them. You seem quite curious and enthusiastic. If you ever feel stuck feel free to message me or any other moderators here on the forum. We are here to help you learn.
Not necessarily. A hard fork will split the blockchain if we have different opinions on the update. If everyone updates or if everyone does not update then there would essentially be no chain split. This is quite hard to achieve and usually any bigger changes may lead to some nodes accepting and some not, resulting in a chain split.
I see. Thanks for the clarification.
1 : a softfork is a change in the blockchain rules, where previous valid blocks become invalid. An hard fork makes previous invalid blocks, valid.
2: If the community of a cryptocurrency want to update the blockchain with other rules, like changing from PoW to PoS. They can make an hard fork so that people that want to stay on the same blockchain continue mining as usual and the other part of the community who want PoS create a new cryptocurrency, using the same blockchain. Itâs a democratic way because you donât force the others in the community to change the system.
3: split community and split chain (you need 100 % of the network to update to avoid a split chain). Someone will stay on the old chain, someone will move to the new one.
Yes, or 0% (no one updates, so there is no split 
)
Homework on forks.
Difference between hard and soft forks:
A. Soft forks are normally preferred because it allows for upgrades that wonât affected the chain from permanently splitting.
B. Hard forks make the chain split into two separate chains that will each do their own thing.
Hard forks might be done if a major bug is found that canât be fixed without changing the structure and rules of the chain. If communities canât come to a compromise on a solution to an issue it can also cause a hard fork.
Risk with hard fork would be splitting the community and losing miners and nodes. This will make the blockchain less secure.
Hard forks expand the rule set and make previously invalid blocks valid. Soft forks contract the rule set and make previously valid blocks invalid.
You would want to do a hard fork if you disagree with the newly proposed rules. You and any other miners who disagree can continue mining the previous chain with a new currency and rule set.
A hard fork will split the community and the hash power.
A hard fork is created when previously invalid blocks are made valid, and a soft fork is created when previously valid blocks are made invalid. If nodes in a network do not wish to conform to a hard fork update, it creates a split resulting in a new community/coin. With a soft fork, as long as the update has >50% of the hash power the update will have majority rule and become the truth and the chain does not split.
To create a new asset/coin. Hard forks expand the rule set and allow for the creation of something new. If there is a disagreement with the protocol of a network, then a hard fork can be created.
A hard fork reduces security by creating a split in the hash power of the network, and also splits a community.
Not necessarily. A hard fork will split the blockchain if we have different opinions on the update. If everyone updates or if everyone does not update then there would essentially be no chain split. This is quite hard to achieve and usually any bigger changes may lead to some nodes accepting and some not, resulting in a chain split.
This is a great example where a hard fork would most probably not cause a chain split. It would be in everyone interest to accept the update in order to still be able to run the network without any bugs or exploits. Thatâs why the third question used the word âriskâ.
A hard fork is a type of update that makes the old nodes incompatible unless they update as well. If everyone updates or if no one updates there wonât be an split in the community, chain or the hash power. While this is not likely it can happen in some cases. Thatâs why we say that performing a hard fork is risky.
What is the difference between a softfork and a hardfork?
A. A softfork is a contraction of the rule set and a hardfork is an expansion of the rule set.
What are some of the reasons why you would do a hardfork?
A. You may do a hardfork because it is democratic, provides a clear path for the update, and there is a new currency.
What are some of the risks with performing a hardfork?
A. A hardfork will split the chain and the community, and there is a new currency.
1.- Soft forks are a contractions of the rule set each block must have to be considered valid by the miners. As it is a contraction, all the nodes keep recognize the new blocks as valid, and only the blocks with outdated rules get discarded. Hard forks are an expansion of the rule set. In this case the there is a split between the community who agrees and disagrees with the new updates.
2.- Because you believe that increasing the rule set for example the block size is an improvement to the network, you may want to increase the number of blocks, etc.
3.- As there is a split in the community and the miners, you decrease the hashpower of the main chain, making it vulnerable for attacks. People will get scammed thinking that they are buying something that in reality it is not. (i.e. Buying BCash instead of Bitcoin)
1.SF renders previously valid blocks invalid by reducing the size of the block this can be
done with 51% of the network.
HS makes invalid blocks valid by increasing the block size splits the chain in two for this
100% approval of the network is needed.
2. Scalability new rules and consensus.
3. Splits the chain in two reduces hash power.
Homework on soft and hard forks:
What is the difference between a soft fork and a hard fork?
A soft fork doesnât require a 100% consensus from the community, a simple majority of at least 51% of the network is enough to initiate a successful soft fork, and this is due to the fact that soft forks decrease the amount of valid blocks, so previously valid blocks will now be invalid, such as the block size, going from 1mB to 0.5mB. Other miners that donât update can still mine new blocks between the 0.5-1mB range, however the majority of updated miners wonât accept those new blocks as valid, so eventually those chains will drop off because the greatest PoW will remain with the updated chain and its blocks.
A hard fork on the other hand, requires a 100% consensus and therefore is harder for the community to agree to it. This is because it makes previously invalid blocks valid, such as increasing the block size from 1mB to 2mB, so if there are miners that donât update and they continue to mine only blocks less than 1mB, that chain will grow faster and the larger blocks will eventually not be accepted since the longer chain with PoW will be the older version because all miners will accept smaller blocks, but not all miners will accept the newer larger blocks.
Hard forks unfortunately often split the community such as the case of BTC and BCH because itâs difficult to reach the 100% community consensus.
What are some of the reasons why you would do a hard fork?
To create a new currency like Bitcoin Cash for example, aimed to create a new currency with a larger block size. Miners involved in a hard fork can continue to work with their own rule set, so in that sense itâs more democratic or at least miners get to choose which chain they want to be a part of.
What are some of the risks with performing a hard fork?
Accidentally creating a new currency (if that wasnât the goal), dividing the community, and subsequently splitting the hash power making both new chains less secure until the hash power increases again.