What is SegWit2x and how could it affect Bitcoin?

A majority of miners has started showing their preference for SegWit2x, a version of Segregated Witness that’s deviating from what Core developers envision to be the solution to bitcoin’s scaling issue. But what is it and what’s leading bitcoin to it?
Recent events have led to increased demand for a solution to bitcoin’s scaling issue. With bitcoin blocks getting filled with transactions as bitcoin’s use is trending near all time high levels and consequently fees al