Vector and Hashtable are legacy code. They are not deprecated but in most cases they can be replaced with other subclasses of List and Map that are better for the job.

Vector and Hashtable are synchronized, but most of the time we don't need synchronization (or already synchronized somewhere else), so using ArrayList or HashMap could improve the performance. If we need to add/remove the elements in a list many times we can use a LinkedList with small performance penalty. If we need to maintain the order of elements in a map we can use LinkedHashMap.