FORKS

Forks in blockchain can simply be seen as any divergence or split that occurs in a blockchain. It can also be seen as a change in the protocol of a blockchain or a situation that take place when more than one block has the same height (That is, block height).
When there is a major hack like what was witnessed in Ethereum some time ago, or there is a big disagreement between the community of the developers of a blockchain like in the case of Bitcoin cash and Bitcoin, then the developers of the blockchain might decide to make some changes to the already existing blockchain's protocol.

Source

HARD FORK

In this type of fork, the previous blockchain will split into two different chains, one of those chains will be entirely different from the old blockchain, it will make use of new rules. This means that the previous blocks will be considered as invalid by the new nodes of the new chain while the old nodes of the previous previous chain will also consider the new blocks of the post-fork as invalid too.
The second chain of the post-fork will still make use of the old rules, it will continue using the old protocol of the pre-fork. This means that the nodes of the chain will still consider the blocks of the post-fork chain as valid.

ETHEREUM HARD FORK

Ethereum previously did a hard fork in their blockchain after an anonymous hacker exploited the vulnerability of the blockchain and made away with digital assets worth tens of millions of dollars.
Due to the major hack incident, the community decided to split what was initially known as The DAO into Ethereum and Ethereum classic. This hard fork was able to move the stolen assets to a recovery address which made it look like such an infamous incident never occurred, therby enabling the users to reclaim their stolen investments.

SOFT FORK

This is the type of fork in which the old or already existing protocol of the blockchain is upgraded to a better protocol without splitting it into two like the case of a hard fork. In this type of fork, the rules are changed in a forward-compatible manner, this means that the nodes in the pre-fork blockchain will still accept blocks from the post-fork blockchain as valid despite the Change in rules brought about by the new software.

BITCOIN TAPROOT SOFT FORK

This fork is aimed at improving the the privacy in Bitcoin. Just like other soft forks, the Taproot soft fork is made to implement some upgrade into the already existing blockchain without splitting it into two.
This fork will help in preventing other users from detecting the complex transactions of another user by improving upon some factors that are related to it.
This fork will be a welcome development for the people advocating for more privacy in Bitcoin because it will cloak the moving parts of Bitcoin transactions that uses complex functionalities, thereby making it look like a single transaction.
Greg Maxwell who is the Bitcoin core developer was the first to unveil this soft fork, it was later merged into the Bitcoin core library in 2020.

BITCOIN CASH

Bitcoin cash is a fork that was proposed to solve scalability issues in he Bitcoin blockchain. Due to the price surge and mainstream traction winessed by ye blockchain in previous times, many investors were turning their attentions to the blockchain and transactions began to pile up, this was due to the 1MB block size limitation.
So Bitcoin was now hard forked to create Bitcoin cash with new block sizes that ranged from 8MB to 32 MB.
The nodes of Bitcoin cash does not validate the original Bitcoin transactions, this shows that it is a hard fork and does not run with the old rules of bitcoin.
Below is the screenshot of Bitcoin cash Genesis block

Genesis_block

Genesis_block_transaction

SEGREGATED WITNESSES

After Bitcoin was hard forked to create another chain with an increased block size, the chain which continued with the old rules was still updated later to increase the block size from that 1MB to 4MB, this is the soft fork that is known as the SEGREGATED WITNESSES.
This became necessary due to the high cost of the Bitcoin protocol which was always about $30, and because of its time consuming nature.
In the updated Bitcoin which is the segregated witnesses, signature data has been removed from the transaction data on all the blocks present in the blockchain.
The segregated witnesses blockchain now accepts 4MB blocks and also accept the previous 1MB blocks which shows that it is a soft fork.
Below is the screenshot of a segregated witnesses block.

Screenshot

THE STEEM AND HIVE HARD FORK

Steem is among those blockchains that has hard forked or split before. The hard fork that occur in Steem was made necessary by the controversial integration of Tron.
That controversy led to the fork of the platform as it formed a branch known as HIVE.

HIVE

HIVE hard forked the steemit network on March 2th last year and STEEM holders participated in their airdrop.
Just like Steem, Hibe is the blockchain that the microblogging platform known as HIVE blog is built on. It has a lot of similarities with Steem; the Hive Backed Dollar replaces the Steem backed dollar, the Hive power replaces the Steem power while HIVE token replaces STEEM token.

SIMILARITIES IN STEEM AND HIVE GENESIS BLOCKS.

Hive is like a branch of Steem, so you don't expect them to exist without some similarities.
In the genesis block of Hive seen in the screenshot below, the witness is initminer, this is the same as that of the steemit Genesis block also shown in the screenshot below.

Steem Genesis block.

Hive Genesis block.

It has the transaction_merkle_root that is made of zeros which shows that no transaction is contained in the block. This is the same thing in the Steem Genesis block.
In the timestamp, the day that the genesis block of Hive was produced is the same as that of Steem, though there is a one-hour time difference.

DIFFERENCES BETWEEN HARD FORK AND SOFT FORK

Hard Fork	Soft Fork
In the hard fork, the previous chain is splitted into two post-fork chains.	In the Soft Fork, the pre-fork chain will not be splitted into two chains, but the previous chain will be updated or upgraded.
The nodes of the new chain recognizes the blocks of the old chain as invalid.	The blocks of the upgraded chain are still recognized as valid by the nodes of the new chain
A hard fork leads to the running of two parallel chains simultaneously with two different coins.	A soft fork only upgrades an existing chain and the blockchain will continue to use one same currency after the fork.
After a hard fork, the protocol of the pre-fork chain is retained in one of the two resulting chains.	In a soft fork, the protocol of the previous chain is updated to a new one.