There are three types of annotations.

1. Marker Annotation - annotation that has no method

@interface CustomAnnotation {}

1. Single-Value Annotation - annotation that has one method

@interface CustomAnnotation {  
    int value();  
}

1. Multi-Value Annotation - annotation that has more than one method

@interface CustomAnnotation{  
    int value1();  
    String value2();  
    String value3();  
}