The form of a serialized object is controlled by the object stream. The Serialization package provides a compact format, either annotated or non-annotated, that provides a choice of representations for primitive data elements

An object stream recursively deconstructs an object graph into pieces of some primitive (built-in) C++ data type. The representation of the data depends on the object stream implementation. If you are using object serialization only to serialize objects and then recreate them with Serialization object streams, the intermediate format is completely transparent to your application. Your choice of formats depends only on considerations of size, speed, and portability. On the other hand, if you plan to do any explicit processing of the object stream contents, the format is an important consideration.