Radix sort vs Counting sort vs Bucket sort. What's the difference?

I am reading the definitions of radix, counting and bucket sorts and it seems that all of them are just the code below:

public static void sort(int[] a, int maxVal){
    int [] bucket=new int[maxVal+1];

    for (int i=0; i<bucket.length; i++){
        bucket[i]=0;
    }

    for (int i=0; i<a.length; i++){
        bucket[a[i]]++;
    }

    int outPos=0;
    for (int i=0; i<bucket.length; i++){
        for (int j=0; j<bucket[i]; j++){
            a[outPos++]=i;
        }
    }
}

I know I can't be right, so what am I missing? Show the code if you think that can help explaining in Java or C.