I am asking simply because of curiosity. I want to read about it, because I really have no clue about it. Simple as that.
Quick summary:
Some scammers wanted to create a new coin using bitcoin name.
They first tried to impose their idea to bitcoin (increase block size), but that idea was rejected by the majority miners.
So they forked the coin and created a new one, called bitcoin cash. Later on, they did anoyhert fork and created another coin, bitcoin sv, whose founder is the faketoshi.
Those fraudsters made a lot of money in both forks.
Later on bitcoin community created the Segwit upgrade, which created the concept of Block weight , virtually increasing Block size without reducing decentralization.
https://en.bitcoin.it/wiki/Segregated_Witness
https://en.bitcoin.it/wiki/Block_size_limit_controversy