i can't remember who said it, but its been claimed java isn't even an oop: its more class oriented programming...
i.e your not really dealing with objects all the time like in smalltalk but just "blueprints" that are a far shadow of what things should be (if i remember the claim correctly)
And Object, in this case (big O), is the name of a class.
Not everything is an object, as someone said, there are also primitives.
There are many other "things" in Java that are not objects (operators, statements, etc.).
Kotlin does set some of this straight. Everything inherits (indirectly) from the Any class. And primitives do not exist in Kotlin (as in Ruby or Smalltalk).
i.e your not really dealing with objects all the time like in smalltalk but just "blueprints" that are a far shadow of what things should be (if i remember the claim correctly)