What else, besides data, is stored during serialization to a JSON format file?

JSON stores only data in the form of key-value pairs, arrays, numbers, boolean values, and null. Serialization to JSON does not preserve:

• Data types: JSON does not have built-in mechanisms for preserving data types (e.g., int, float, string from C++). The type is determined by the format of the value.
• Pointers and references: Pointers and references to objects or data outside the serializable structure are not preserved.
• Member functions: The behavior of objects (functions, methods) is not serialized. JSON only represents state.
• Class and hierarchy information: Serialization to JSON does not preserve class structure, inheritance, or namespace information.
• Static members: Static data or functions are not part of a specific object instance and are not serialized.
• Virtual table information (vtable): Mechanisms of polymorphism related to virtual functions are not preserved.