Examples.

String car = "car";
String car2= "car";
System.out.println(car != car2);
System.out.println(car == car2);

If we run above code, we will have output as:
false
true

String car = "car";
String car3 = new String("car");
System.out.println(car != car3);
System.out.println(car == car3);

if we run above code, we will have output as:
true
false