Property

java.util.List

java.util.Set

1- 

Insertion order

java.util.List is ordered collection it maintain insertion order in java.

Most of the java.util.Set implementation does not maintain insertion order.

HashSet does not maintains insertion order in java.

Thought LinkedHashSet maintains insertion order in java.

TreeSet is sorted by natural order in java.

2-

Duplicate elements

List allows to store duplicate elements in java.

Set does not allow to store duplicate elements in java.

3

Null keys

List allows to store many null keys in java.

Most of the Set implementations allow to add only one null in java.

TreeSet does not allow to add null in java.

4-

Getting element on specific index

List implementations provide get method to get element on specific index in java.

ArrayList, Vector, copyOnWriteArrayList and LinkedList provides -

get(int index)

Method returns element on specified index.

Get method directly gets element on specified index. Hence, offering O(1) complexity.

Set implementations does not provide any such get method to get element on specified index in java.

5-

Implementing classes

ArrayList, LinkedList, Vector, CopyOnWriteArrayList classes implements List interface in java.

HashSet, CopyOnWriteArraySet, LinkedHashSet, TreeSet, ConcurrentSkipListSet, EnumSet classes implements Set interface in java.

6-

listIterator

listIterator method returns listIterator to iterate over elements in List in java.

listIterator provides additional methods as compared to iterator like

hasPrevious(), previous(), nextIndex(), previousIndex(), add(E element), set(E element)

Set does not provide anything like listIterator. It simply return Iterator in java.

7-

Structure and resizable

List are Resizable-array implementation of the java.util.List interface in java.

Set uses Map for their implementation.

Hence, structure is map based and resizing depends on Map implementation.

Example > HashSet internally uses HashMap.

8-

Index based structure /RandomAccess

As ArrayList uses array for implementation it is index based structure, hence provides random access to elements.

But LinkedList is not indexed based structure in java.

Set is not index based structure at all in java.