where is the difference between these two file modes ?

https://en.cppreference.com/w/c/io/fopen#File_access_flags

https://en.cppreference.com/w/c/io/fopen#File_access_flags

#include <stdio.h>

int main(){
    FILE *file = fopen("test.txt", "w+");

    char buffer[992];


    fscanf(file, "%s", buffer);

    printf("%s", buffer);
    
}

#include <stdio.h>

int main(){
    FILE *file = fopen("test.txt", "w+");

    char buffer[992];


    fscanf(file, "%s", buffer);

    printf("%s", buffer);
    
}

░dVJf☺

░dVJf☺

#include <stdio.h>

int main(){
    FILE *file = fopen("test.txt", "w");

    fprintf(file, "hello world");


    char buffer[443];
    fscanf(file, "%s", buffer);
    printf("%s", buffer);
}

#include <stdio.h>

int main(){
    FILE *file = fopen("test.txt", "w");

    fprintf(file, "hello world");


    char buffer[443];
    fscanf(file, "%s", buffer);
    printf("%s", buffer);
}