class A { }

class B extends A { }

Object o1 = new A(); 
Object o2 = new B();

o1 instanceof A => true 
o1 instanceof B => false 
o2 instanceof A => true // <================ HERE 
o2 instanceof B => true

o1.getClass().equals(A.class) => true 
o1.getClass().equals(B.class) => false 
o2.getClass().equals(A.class) => false // <===============HERE 
o2.getClass().equals(B.class) => true

getClass() will be useful when you want to make sure your instance is NOT a subclass of the class you are comparing with.