Two dimensional array is a form of matrix in which users can have rows and columns as per need. We can think of table in which x no.of rows and y no.of columns are available.

Syntax: 

int item = a[i,j]

This is a two dimensional array which contains i no. of rows and j no. of columns, Here a represents the array and i and j are also used to define each array of element,it is used as a subscript.

Let's take an example to initialize a two dimensional array:

This array is with 3 rows and each row has 4 columns.

int [,] a = new int [3,4] {
col[0][1][2][3]
   {0, 1, 2, 3} ,   /*   row  [0] */
   {4, 5, 6, 7} ,   /*   row  [1] */
   {8, 9, 10, 11}   /*   row  [2] */
};

refer screenshot for an example:

Let's Create a program to handle the 2-dimensional array:

using System;
namespace TwodimensionalArrayApplication
{
   class MytwoDimensionalArray
   {
      static void Main(string[] args)
      {
         /* an array with 4 rows and 2 columns*/
         int[,] a = new int[4, 2] 
 		{ {0,0}, 
		{1,2}, 
		{3,4},
 		{5,6} };
         int i, j;
         
         /* output each array element's value */
         for (i = 0; i < 4; i++)
         {
            for (j = 0; j < 2; j++)
            {
               Console.WriteLine("a[{0},{1}] = {2}", i, j, a[i,j]);
            }
         }
         Console.ReadKey();
      }
   }
}

when program will be executed,output will be:

a[0,0]: 0
a[0,1]: 0
a[1,0]: 1
a[1,1]: 2
a[2,0]: 3
a[2,1]: 4
a[3,0]: 5
a[3,1]: 6