What are command line arguments (argc and argv)?

main.c

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

int main(int argc, char* argv[]) {
    int i;
    for (i = 0; i < argc; i++) {
        printf("argv[%d]: %s\n", i, argv[i]);
    }
    
    int result = 1;
    for (i = 1; i < argc; i++) {
        int x = strtol(argv[i], NULL, 10);
        result = result * x;
    }
    printf("Multiplication result is %d\n", result);
    return 0;
}