When you use a string literal the string can be interned, but when you use new String("...") you get a new string object.
In this example both string literals refer the same object:
String a = "abc";
String b = "abc";
System.out.println(a == b); // true
Here, 2 different objects are created and they have different references:
String c = new String("abc");
String d = new String("abc");
System.out.println(c == d); // false
In general, you should use the string literal notation when possible. It is easier to read and it gives the compiler a chance to optimize your code.
