The term, “Chain Split” is another name for the concept of “fork”.
It refers to the break in digital recordings commonly known as a blockchain which had been developed by computers that run the cryptocurrency technology. With cryptocurrencies, a singular block should be produced at a time. If it does not, then a Chain Split happens.
A Chain Split or a fork is a result of a disagreement of network users who manage cryptocurrency technology regarding how blocks should be made. An example of a Chain Split is what happened to Ethereum back in 2016, giving crypto traders Ethereum and Ethereum classic.