There, it is defined as:
Serialization lets you take an object or group of objects, put them on a disk or send them through a wire or wireless transport mechanism, then later, perhaps on another computer, reverse the process: resurrect the original object(s). The basic mechanisms are to flatten object(s) into a one-dimensional stream of bits, and to turn that stream of bits back into the original object(s).
XML is frequently used to serialize objects and such these days. There are many packages that will help you with that for Java, C, C++, and other languages. And don't forget, you still need to de-serialize it at the other end of the connection. This may not be trivial.