Collections

Common collection activities include adding objects, removing objects, verifying object inclusion, retrieving objects, and iterating.
Three meanings for "collection":
* collection: Represents the data structure in which objects are stored
* Collection: java.util interface from which Set and List extend
* Collections: A class that holds static collection utility methods

Four basic flavors of collections include Lists, Sets, Maps, Queues:
* Lists of things Ordered, duplicates allowed, with an index.
* Sets of things May or may not be ordered and/or sorted; duplicates
not allowed.
* Maps of things with keys May or may not be ordered and/or sorted;duplicate keys are not allowed.
* Queues of things to process Ordered by FIFO or by priority.

Four basic sub-flavors of collections Sorted, Unsorted, Ordered, Unordered.
* Ordered Iterating through a collection in a specific, non-random order.
* Sorted Iterating through a collection in a sorted order.
* Sorting can be alphabetic, numeric, or programmer-defined