Pointer to Structure

struct book
{
    int id;
    float price;
    char name[15];
};
int main()
{
        struct book b1 = {1,250.75,"ABC"};
        display(&b1);

        return 0;
}

void display(struct book* pbook)
{
    printf("%d\t%f\t%s",pbook->id,pbook->price,pbook->name);
}   

Address of b1 variable of book structure is passed to function display.It is collected in pointer to book structure.

You access members of structure through pointer using ->(arrow operator) or . (dot operator)

Remember that 

pbook->id = (*pbook).id