what's the difference between char *s[] and char s[][20] in C?

Check this first code, If I write char *tracks[] instead of char tracks[][80], it seems still working same perfectly.

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

char tracks[][80] = { "I left my heart in Harvard Med School",
        "Newark, Newark - a wonderful town", "Dancing with a Dork",
        "From here to maternity", "The girl from Iwo Jima", };

void find_track(char search_for[]) {    //'char *search_for' is equivalent.
    int i;
    for (i = 0; i < 5; i++) {
        if (strstr(tracks[i], search_for))
            printf("Track %i(Line %i):'%s'\n", i, i + 1, tracks[i]);
    }
}

int main() {
    char search_for[80];
    printf("Search for: ");
    scanf("%79s", search_for);  //fgets(search_for,80,stdin);
    find_track(search_for);
    return 0;
}

But check this second code, If I try to use char juices[][20] instead of char *juices[] , the compiler give error, I want to know why?

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

void print_reverse(char *s) {
    size_t len = strlen(s);
    char *t = s + len - 1;
    while (t >= s) {
        printf("%c", *t);
        t = t - 1; //pointer arithmetic
    }
    puts("");
}

int main() {
    char *juices[] = { "dragonfruit", "waterberry", "sharonfruit", "uglifruit",
            "rumberry", "kiwifruit", "mulberry", "strawberry", "blueberry",
            "blackberry", "starfruit" };

    char *a;

    puts(juices[6]);
    print_reverse(juices[7]);
    a = juices[2];
    juices[2] = juices[8];
    juices[8] = a;
    puts(juices[8]);
    print_reverse(juices[(18 + 7) / 5]);

    puts(juices[2]);
    print_reverse(juices[9]);
    juices[1] = juices[3];
    puts(juices[10]);
    print_reverse(juices[1]);

    return 0;
}