A group of objects is represented by a collection in C#, which is also used to perform different operations on objects.
Thus the C# collections perform all the data structure work. Just like an array, a collection can also be used to store objects with an advantage over an array. In a collection, the stored object can grow or shrink dynamically, however, in an array, there is a size limit.
The classes of the System.Collections.Generic namespace are listed below:
List Stack Queue LinkedList HashSet SortedSet Dictionary SortedDictionary SortedList
The classes of the System.Collections namespace are listed below:
ArrayList Stack Queue Hashtable
The classes of the System.Collections.Concurrent namespace are listed below:
BlockingCollection ConcurrentBag ConcurrentStack ConcurrentQueue ConcurrentDictionary Partitioner Partitioner OrderablePartitioner