| ArrayList | ConcurrentArrayList |
| It is not Thread safe | It is ThreadSafe since a copy of list is created on which updates are performed |
| While one thread is iterating other thread write into the list we will get concurrentModifciationException | Does not give ConcurrentModificationException when added to ArrayList while Iterating |
| Iterator is failfast | Iterator is failsafe |
| Iterator is ArrayList can remove | Iterator is CopyOnWriteArrayList cannot remove throw UnsupportedOperationException |
| Introduced in java v1.2 | Introduced in java v1.5 |
