Biggest difference as per my knowledge - Collections(ArrayList, Vector, LinkedList, Queue, Hashtable, TreeMap, LinkedHashMap, LinkedHashSet, TreeSet) play important role in Java; no equivalent in OO ABAP. Internal tables and work area can be used whenever we need collection i.e. to process...
The major difference between List and Set that distinguishes them is List is a collection of ordered element. On the other hand, Set is a collection of objects where the collection does not allow duplicate elements in it.