What is serialization? How would you exclude a field of a class from serialization?

Serialization is a process of reading or writing an object. It is a process of saving an object’s state to a sequence of
bytes, as well as a process of rebuilding those bytes back into a live object at some future time. An object is
marked serializable by implementing the java.io.Serializable interface, which is only a marker interface -- it simply
allows the serialization mechanism to verify that the class can be persisted, typically to a file.