Introduce C# Collections

Collection that provides by .Net Framework have stacks, queues, lists, and hash tables. Collection classes are defined under System.Collections or System.Collections.Generic namespace.
At more complex, an object holds references to many other objects. The collections we often using is List and Dictionary.
Different between stacks, queues, lists, and hash tables

Declare a Dictionary
When you Create a Dictionary instance, you needed to pass in <TYPE,TYPE>,to tell that which type of Dictionary you want to Create.See Also GENERICS
Eg

 Dictionary<TYPE, TYPE> objectInstance = new Dictionary<TYPE, TYPE>();

Example(Here i'm using Dictionary)

using System;
using System.Collections.Generic;
using System.Collections;
using System.Linq;
using System.Text;

namespace IntroduceCollection
{
    class IntroduceCollection
    {
        static void Main()
        {
            Dictionary<string, string> carPlateNum = new Dictionary<string, string>()
            {
                {"john", "JKE 1333"},
                {"jess", "QQ 1314"},
                {"apple", "JK 8888"},
                {"jack", "USS 1555"},
                {"alice","AC 6666"}
            };
            // Using LIST to store car OwnerName
            List<string> ownerName = new List<string>(carPlateNum.Keys);

            /* Output all the CarPlate Data *
             *                              */
            Console.WriteLine("Owner\tPlate Number");
            foreach (string name in ownerName)
            {
                Console.WriteLine("{0}\t{1}", name, carPlateNum[name]);
            }
            //end Output with using LIST

            //Direct output
            Console.WriteLine("Foreach looping Output content of Dictionary");
            foreach (KeyValuePair<string, string> carInfo in carPlateNum)
            {
                Console.WriteLine("{0}\t{1}", carInfo.Key, carInfo.Value);
            }

            Console.ReadLine();
        }
    }
} 

Example above i'm create a Dictionary to store Owner and Car Plate Number .Then output the information.