So, implement the Serializable interface when you need to store a copy of the object, send them to another process which runs on the same system or over the network. Because you want to store or send an object. It makes storing and sending objects easy.

Why do we use Serializable in Java?

Serialization in Java allows us to convert an Object to stream that we can send over the network or save it as file or store in DB for later usage. Deserialization is the process of converting Object stream to actual Java Object to be used in our program.

What happens if we implement Serializable?

If a super class implements Serializable, then its sub classes do automatically. When an instance of a serializable class is deserialized, the constructor doesn't run. If a super class doesn't implement Serializable, then when a subclass object is deserialized, the super class constructor will run.