在c中使用fread时,为什么要将结构转换为char*？

#include<stdio.h>
#include <stdlib.h>

typedef struct {
    int a;
    int b;
} MyStruct;

int main() {
    MyStruct s;
    s.a = 1;
    s.b = 2;

    FILE *f = fopen("data.bin", "wb");
    if (f == NULL) {
        printf("Error opening file!\n");
        return 1;
    }

    fwrite(&s, sizeof(MyStruct), 1, f);
    fclose(f);

    f = fopen("data.bin", "rb");
    if (f == NULL) {
        printf("Error opening file!\n");
        return 1;
    }

    MyStruct s2;
    fread((char*)&s2, sizeof(MyStruct), 1, f);
    fclose(f);

    printf("s.a = %d, s.b = %d\n", s2.a, s2.b);

    return 0;
}