Purpose of marker interfaces in Java

Marker interface is an empty interface (no field or methods). Examples of marker interface are Serializable, Clonnable, Remote and ThreadSafe interfaces. 

Note: Marker interface is used to inform the JVM that the classes implementing them will have some special behavior.

 In java we have following four major marker interfaces:

• Searilizable interface

• Cloneable interface

• Remote interface

• ThreadSafe interface

public interface Serializable 
{
  // nothing here
}

Q. Marker interface won't contain any method then how the objects will get that special ability?

Ans. JVM is responsible to provide required ability in marker interfaces