What are the three dots in Java?

class main {
    public static int function (int ... a) {
      int sum = 0;
      for (int i : a)
           sum += i;
        return sum;
    }
    public static void main( String args[] ) {
        int ans = function(1,1);
        System.out.println( "Result is "+ ans );
    }
}

class main {
    public static int function (int ... a) {
      int sum = 0;
      for (int i : a)
           sum += i;
        return sum;
    }
    public static void main( String args[] ) {
        int ans = function(1,1,1);
        System.out.println( "Result is "+ ans );
    }
}