Working of serializable interface, when it doesn't have any methods

Hi,
I am curious about how the serializable interface is used in JVM.
This is an empty interface. ie. it does not have any method signatures or any variables inside.
How does java use this interface, for serializing purposes.
Also, why should it be an interface, when its all empty.

Such marker interfaces are just used to tell something about about a class, in this cases that the developer wants that instances of a class can be serialized. The code that handles the serialization just check s"instanceof Serializable". Of course Serializbale could look like this
public interface Serializable
public boolean isSerializable();
But why make things more complicated than necessary?

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