订购…列表有顺序，集合没有。

这可能不是您想要的答案，但是集合类的JavaDoc实际上非常具有描述性。复制/粘贴:

An ordered collection (also known as a sequence). The user of this interface has precise control over where in the list each element is inserted. The user can access elements by their integer index (position in the list), and search for elements in the list. Unlike sets, lists typically allow duplicate elements. More formally, lists typically allow pairs of elements e1 and e2 such that e1.equals(e2), and they typically allow multiple null elements if they allow null elements at all. It is not inconceivable that someone might wish to implement a list that prohibits duplicates, by throwing runtime exceptions when the user attempts to insert them, but we expect this usage to be rare.

List是项的有序分组 Set是一个无序的项目分组，不允许重复(通常)

从概念上讲，我们通常将允许重复的无序分组称为Bag，而不允许重复的无序分组称为Set。

最大的不同在于基本概念。

从设置和列表界面。集合是数学概念。设置方法扩展集合。但是没有添加新的方法。size()表示基数(more为BitSet。基数，线性计数器，日志日志，HyperLogLog)。addAll()表示联合。retainAll()表示交集。removeAll()表示差异。

However List lack of these concepts. List add a lot of method to support sequence concept which Collection interface not supply. core concept is INDEX. like add(index,element),get(index),search(indexOf()),remove(index) element. List also provide "Collection View" subList. Set do not have view. do not have positional access. List also provide a lot of algorithms in Collections class. sort(List),binarySearch(List),reverse(List),shuffle(List),fill(List). the method params is List interface. duplicate elements are just the result of concepts. not the essential difference.

所以本质的区别在于概念。集合是数学集合的概念。列表是序列的概念。

List Vs Set

1) Set不允许重复。列表允许重复。基于Set的实现，它还维护插入顺序。

LinkedHashSet。它维护插入顺序。请参考此处

2)包含方法。根据集合的性质，它将为访问提供更好的性能。最好的情况是o(1)但是List有调用contains的性能问题。

嗨，已经给出了这么多答案，让我指出一些到目前为止没有提到的地方:

大多数的List实现(ArrayList,Vector)实现了RandomAccess接口，这是一个快速访问的标记接口。Set的实现都没有这样做。 List使用一个特殊的迭代器，称为ListIterator，它支持双向迭代。Set使用只支持单向迭代的迭代器 HashSet占用的内存是ArrayList的5.5倍 相同数量的元素。