Program to understand how a pointer to structure variable is sent to a function

#include<stdio.h>
#include<conio.h>
struct student
{
char name[20];
int rollno;
int marks;
};
void display(struct student *);
void inc_marks(struct student *);
main( )
{
struct student stu1 = {"John", 12, 87};
struct student stu2 = {"Mary", 18, 90};
inc_marks(&stu1);
inc_marks(&stu2);
display(&stu1);
display(&stu2);
}
void inc_marks(struct student *stuptr)
{
(stuptr->marks)++;
}   
void display(struct student *stuptr)
{
printf("Name   - %s\t", stuptr->name);
printf("Rollno - %d\t", stuptr->rollno);
printf("Marks  - %d\n", stuptr->marks);
}