understand pointers to structures

/*P2.26 Program to understand pointers to structures*/
#include<stdio.h>
struct student {
        char name[20];
        int rollno;
        int marks;
           };
main( )
{
    struct student stu = {"Mary", 25, 68};
    struct student *ptr = &stu;
    printf("Name  - %s\t", ptr->name);
    printf("Rollno  - %d\t", ptr->rollno);
    printf("Marks  - %d\n", ptr->marks);
}