Difference between Class<?> and Class<Object> in Java [duplicate]

Question

What is the difference between Class<?> and Class<Object> in Java? AFAIK Java Erasure changes <?> to it's upper bound, which in this case would be Object anyway. So what is this for?

Answer 1

the difference is that Collection<String> is not a subtype of Collection<Object>, Collection<?> is usable in place as an argument where any collection can be put