Collection - Still working on... ! :)

Collections	Dynamic Array	Fast lookup	Required Cast	Good Choice for Booleans	Thread safety	Stores Any type object	Linear Array	Loop	Comments
List	Yes	Not good	No	No	no	No(Except List<object> )	Yes	It is fast because it is Linear
Dictionary	Yes	Yes	No	No	No
ArrayList	yes	No	Yes	No	No	Yes	Yes
Hashtable		Yes							It is an older .NET Framework type.
ConcurrentDictionary	Yes	Yes	No	No	Yes	No
ConcurrentBag									Sometimes lookup functionality is not required. ConcurrentBag allows us to safely Add and Take results
BitArray				yes					The program creates a bool array with true and false values, and then the BitArray constructor converts those into one bit each. This means that instead of one byte for a bool, the values are stored as one bit, in one-eighth the space.
Tuple									A Tuple has many items. Each item can have any type. The Tuple class provides a unified syntax for creating objects with typed fields.
KeyValuePair									Tuple was faster in every test than KeyValuePair except in allocation performance.
Stack
Queue
HashSet									HashSet is an optimized set collection. It helps eliminates duplicate strings or elements in an array. It provides a simple syntax for taking the union of elements in a set. This is performed in its constructor. Constructor   Example. This program contains a source array that contains several duplicated strings. It eliminates duplicate strings in the array. The program calls the HashSet constructor to transform the array elements into a set data structure.   When the source input becomes large with thousands of elements, hashed collections are faster.
SortedSet									SortedSet is an ordered set collection. We have many elements and want to store them in a sorted order and also eliminate all duplicates from the data structure. The SortedSet is part of the System.Collections.Generic namespace.
Lazy									This type implements the lazy instantiation pattern. We look into the concept of thunks, as described in a programming textbook. The Lazy class has no relation to the Sleep method.
HybridDictionary									HybridDictionary attempts to optimize Hashtable. It implements a linked list and hash table data structure, switching over to the second from the first when the number of elements increases past a certain threshold.