Why is factory method a class pattern, while an abstract factory an object pattern?

From GOF book:

Class patterns deal with relationships between classes and their subclasses. These relationships are established through inheritance, so they are static-fixed at compile-time. Object patterns deal with object relationships, which can be changed at run-time and are more dynamic. Almost all patterns use inheritance to some extent. So the only patterns labeled "class patterns" are those that focus on class relationships.

Why is factory method a class pattern, and abstract factory an object pattern, given that they seem to be very similar patterns?

Thanks.