Marker interface is used as a tag that inform the Java compiler by a message so that it can add some special behavior to the class implementing it. Java marker interface are useful if we have information about the class and that information never changes, in such cases, we use marker interface represent to represent the same. Implementing an empty interface tells the compiler to do some operations.
It is used to logically divide the code and a good way to categorize code. It is more useful for developing API and in frameworks like Spring.
