var numbers = new[] {1,2,3,4,5,6,7,8,9,10};
var someNumbers = numbers.Where(n => n < 6);
Console.WriteLine(someNumbers.GetType().Name);
//WhereArrayIterator`1
var someNumbersList = someNumbers.ToList();
Console.WriteLine(
someNumbersList.GetType().Name + " - " +
someNumbersList.GetType().GetGenericArguments()[0].Name);
//List`1 - Int32