"Object" as in Java is a type for any tagged box type. Primitives, such as "int", don't derive from Object, but can be promoted to a corresponding boxed type, such as "Integer".
The story is a little more complex in C#, where ValueType derives from Object and "value types", both primitive and user-defined, are truly subclasses of Object. Types not derived from ValueType are considered reference types.
"Object" as in Java is a type for any tagged box type. Primitives, such as "int", don't derive from Object, but can be promoted to a corresponding boxed type, such as "Integer".
The story is a little more complex in C#, where ValueType derives from Object and "value types", both primitive and user-defined, are truly subclasses of Object. Types not derived from ValueType are considered reference types.