class A; end A.ancestors [A, Object, Kernel, BasicObject]
As we can see here that when we create a very basic class it still inherits from two other classes and module.
So every class that we have created is inherited from Object and Object inherits from BasicObject.
The structure of Object would be somewhat similar to BasicObject → Object (module Kernel mixes in)→ MyClass
class BasicObject “7 methods” end module Kernel “over 100 methods” end class Object < BasicObject include Kernel end class A < Object end