Shellcode in C - What does this mean?

I'm not really getting how this code does what it does:

char shellcode[] = "\xbb\x00\x00\x00\x00"           
                   "\xb8\x01\x00\x00\x00"                  
                   "\xcd\x80";                  

int main()
{
    int *ret;
    ret = (int *)&ret + 2;
    (*ret) = (int)shellcode;
}

Okay, I know:

int *ret;

sets a pointer of int. and:

ret = (int *)&ret + 2;

sets the address of ret and 2 bytes (I think.)

But I don't get what this means:

(int *)&ret

I know what &ret means but not what (int *)&ret means. Also, how does it execute the shellcode by assigning the value of shellcode to ret?

UPDATE: What is the difference between:

(int *)&ret  + 2

and:

&ret + 2