Describe about the various types of generic collections?

There are basically four different types of generic collections which are as follows:-

1. List:-Lists are indexed based Generic Collections. Lists are Generic form of ArrayList.

List helps us to create flexible strong type collection as you can see in below code snippet i have defined List as "int" and "string".

////index based Generic collection           
List<int> ObjInt = new List<int>();        
ObjInt.Add(123);           
ObjInt.Add(456);           
Console.WriteLine(ObjInt[0]); //accessing the List by internal index based value.           
List<string> ObjString = new List<string>();           
ObjString.Add("feroz");

2. Dictionary:-Dictionary are key based generics collection.

Dictionary are generic form of Hashtable.

////key based Generic collection           
Dictionary<int, int> ObjDict = new Dictionary<int,int>();           
ObjDict.Add(1,2);           
Dictionary<int, string> ObjDict1 = new Dictionary<int,string>();           
ObjDict1.Add(3, "feroz is a developer");           
ObjDict1.Add(4, "wasim is a developer");           
Console.WriteLine(ObjDict1[3]); //accessing the dictionary by defined key.

3. Stack:-Stack generic collection allows you to get value in "LIFO"(last in first out) manner.

//// Stack            
Stack<string> ObjStack = new Stack<string>();           
ObjStack.Push("feroz");           
ObjStack.Push("moosa");           
Console.WriteLine(ObjStack.Pop());

4. Queue:-Queue generic collection allows you to get value in "FIFO"(first in first out) manner.

////Queue           
Queue<int> ObjStr = new Queue<int>();           
ObjStr.Enqueue(789);           
ObjStr.Enqueue(456);           
Console.WriteLine(ObjStr.Dequeue());