Ummm... you can add elements at the beginning, middle, or end of either structure. But in some cases, the performace is good - in others, it's really bad. Vectors are good for adding or removing elements near the end - the further you are from the end, the slower it is. LinkedLists are not quite as fast as Vectors at the end of the list, but they're no slower at the beginning or middle, which makes them much better than Vectors for that type of work. Angela, most of the detailed differences are discussed at length in other forums here - specifically, "Java in General (intermediate)" and "Performance". Try using "search" (in the upper right corner of your screen) to find past discussions in those forums. At the beginner level, all Lists (Vector, ArrayList, LinkedList) are pretty much interchangeable.