Question

Annotations which are applied to other annotations are called meta annotations

Answer 1

Explanations / annotations connected to different annotations (otherwise called "Meta Annotations"):  

@Retention - Specifies how the checked comment is put away—Whether in code just, arranged into the class, or accessible at runtime through reflection.  

@Documented - Marks another explanation for incorporation in the documentation.  

@Target - Marks another explanation to confine what sort of Java components the comment might be connected to.  

@Inherited - Marks another comment to be acquired to sub-classes of clarified class (as a matter of course explanations are not acquired to sub-classes)