**Collections Reference can have any of these objects.
| Name | Type | Parent | Since | Detail |
| AbstractCollection | Class | java.lang.Object | 1.2 | Link |
| AbstractList | Class | java.util.AbstractCollection | 1.2 | Link |
| AbstractQueue | Class | java.util.AbstractCollection | 1.5 | Link |
| AbstractSequentialList | Class | java.util.AbstractList | 1.2 | Link |
| AbstractSet | Class | java.util.AbstractCollection | 1.2 | Link |
| ArrayBlockingQueue | Class | java.util.AbstractQueue | 1.5 | Link |
| ArrayDeque | Class | java.util.AbstractCollection | 1.6 | Link |
| ArrayList | Class | java.util.AbstractList | 1.2 | Link |
| Collections | Class | java.lang.Object | 1.2 | Link |
| ConcurrentLinkedDeque | Class | java.util.AbstractCollection | 1.7 | Link |
| ConcurrentLinkedQueue | Class | java.util.AbstractQueue | 1.5 | Link |
| ConcurrentSkipListSet | Class | java.util.AbstractSet | 1.6 | Link |
| CopyOnWriteArraySet | Class | java.util.AbstractSet | 1.5 | Link |
| DelayQueue | Class | java.util.AbstractQueue | 1.5 | Link |
| EnumSet | Class | java.util.AbstractSet | 1.5 | Link |
| HashSet | Class | java.util.AbstractSet | 1.2 | Link |
| LinkedBlockingDeque | Class | java.util.AbstractQueue | 1.6 | Link |
| LinkedBlockingQueue | Class | java.util.AbstractQueue | 1.5 | Link |
| LinkedHashSet | Class | java.util.HashSet | 1.4 | Link |
| LinkedList | Class | java.util.AbstractSequentialList | 1.2 | Link |
| LinkedTransferQueue | Class | java.util.AbstractQueue | 1.7 | Link |
| PriorityBlockingQueue | Class | java.util.AbstractQueue | 1.5 | Link |
| PriorityQueue | Class | java.util.AbstractQueue | 1.5 | Link |
| Stack | Class | java.util.Vector | 1.0 | Link |
| SynchronousQueue | Class | java.util.AbstractQueue | 1.5 | Link |
| TreeSet | Class | java.util.AbstractSet | 1.2 | Link |
| Vector | Class | java.util.AbstractList | 1.0 | Link |