The simplest way to create a string in Java is with a string literal. You wrap text in double quotes and assign it to a variable:
String greeting = "Hello";
String empty = "";
Double quotes are required. Single quotes are for char values, not strings. If you write String s = 'H'; the compiler will reject it because 'H' is a char, not a String.
You can also place the literal directly in a method call without storing it first:
System.out.println("Welcome to Java");
Every time you write a string literal in your code, Java creates a String object behind the scenes. That object is what your variable points to.