How do we talk about class for a return value or a parameter?

HFEJB page 77.

"When you pass a serialized object as an argument or return value, you better make sure the class file for the type you are passing is available on the other side. If the class isn't there, the object will never deserialize"

"That includes the stub classes. if the client doesn't have the class for the stub object, its hopeless.."

I didn't quite get what the "class file for the type means. I really don't have clue what they are saying here or i am misinterpreting something.

Please clarify.

Thanks.

[ September 15, 2004: Message edited by: piyush jain ]

The explanation from Kathy might help at this link
http://www.coderanch.com/t/159878/java-EJB-SCBCD/certification/stubs-client

Thanks Shreyas.

When you pass a serialized object as an argument or return value, you better make sure the class file for the type you are passing is available on the other side. If the class isn't there, the object will never deserialize

I understand what Kathy said about the Stub objects and classes.

But what does

when you pass a serialized object as an argument or return value make sure the class file for the type you are passing

mean? how can we have a class for the return value? is it referring the client class thats passing the parameters? or in other case the bean class which has the business methods and returning values?

can somebody clarify with an example?

Thanks.