What are the parameters in splte?

Question

Java

I solve problems on codewars, and in one solution I saw

public static String[] solution(String s) {
        s = (s.length() % 2 == 0)?s:s+"_";
        return s.split("(?<=\\G.{2})");
    }

What do the characters in split mean?

Answer 1

This is a regular expression.