When you need to get data out of your program, out of it's process memory, you need to shape it in a linear string - serialize. It doesn't have to be a text string, you have standard binary serialization formats, or you can roll your own (don't). And on the other side, you deserialize from this linear string into objects stored in (another) program's process memory. You most often can't just raw copy data from process memory because that data is not tagged, in no standard order or format, not linear, not stored in one place, or contains information that would be wrong in other program's memory, like pointers and metadata. More on reddit.com

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On a related note, Brian Goetz has called Java serialization one of the biggest design mistakes in Java, and you shouldn't use it at all. More on reddit.com

"reflection makes it possible to do serialization and deserialization in a completely generic manner" You can get all the member fields of the object ragardless of the object's type using reflection. generate special marshalling functions for each type of object" Marshalling is the practice of converting your object into another format like XML or JSON. More on reddit.com