Difference between two lists

Question

I Have two generic list filled with CustomsObjects.

I need to retrieve the difference between those two lists(Items who are in the first without the items in the sec

Answer 1

        List list1 = new List();
        List list2 = new List();
        List listDifference = new List();

        foreach (var item1 in list1)
        {
            foreach (var item2 in list2)
            {
                if (item1 != item2)
                    listDifference.Add(item1);
            }
        }