Java - extending a class and reusing the methods?

public class BaseClass {
   public void start() {
      // do something
   }
}

public class ClassA extends BaseClass {

}

ClassA c = new ClassA();
c.start();

In the following code I want to use the start() method as it was defined in the super class, I have seen in a lot of other developer's codes that they override the method in the super class and then they call the super. is there a reason for that?

public class ClassA extends BaseClass {
   @Override
   public void start() {
      super.start();
   }
}