Serialization is the process of saving the state of an 
object by converting it to a stream of bytes

serialization is process of converting object into stream

Serialization is a process of converting object into stream
of bytes.

Types of Serialization 

1)XML Serialization
2)SOAP Serialization
3)Binary Serialization
4)Custom Serialization

In XML Serialization we can convert only public objects into
stream of bytes, where as in SOAP and Binary Serialization
we can convert private objects also. 

In XML Serialization we can able to convert only objects
into stream of bytes, but in Binary Serialization we can
convert all the objects(Objects in Object) also.

SERIALIZATION:
            serialization is the process of converting an 
object or a graph of object in to a linear sequence of 
bytes or stream.

All the above descriptions are corret.

Seriallization is done for the faster accessing of remote 
object. So it is mainly used in remoting. 
Remoting is a concept in .Net which helps to access/make 
use of remote (through internet) application(/object).
So the object requested is converted in to stream of bytes 
and get transfered to the requsted application.