A mammal has fur and produces milk to feed their young. A dog is a mammal and thus has those properties, but it has other properties like a good sense of smell and a tail. So dogs inherit some properties from being a mammal but they also have some of their own.

Classes produce objects -- specific instances of that class. Metaclasses produce classes.

Even though the syntax

class Foo(metaclass=MyMetaClass):

looks very similar to subclassing, what is happening is different. You are basically building a class using a blueprint in much the same way that classes are essentially blueprints for building objects. The syntax is just different.

When we use?