Array can be easily
defined as a variable that hold multiple elements
which has the same data type. C uses arrays as a way
of describing a collection of variables with
identical properties.

type
variable_name[lengthofarray];

*Simple Program
showing an array of 5 elements. *

In this case we have
ages[5] as an array. i.e
ages[0],ages[1],ages[2],ages[3],ages[4].

__
Example of Array
Declaration:__

double arr[100]

Another example :

int myArray[5] = {1, 2,
3, 4, 5}; //declaring and initialize the array in
one statement

int number[4];

number[0]=14;

number[1]=13;

number[2]=15;

number[3]=16;

__Declaration of a 2D array in C language:__

int x[3][2] - matrix 3X2 (3 rows, 2 columns(

Example:

int array[3][3] = {1, 2,
3, 4, 5};

array[0][0] = 1

array[0][1] = 2

array[0][2] = 3

array[1][0] = 4

array[1][1] = 5

array[1][2] = 0

array[2][0] = 0

array[2][1] = 0

array[2][2] = 0

See this program of
Matrix Multiplication using the concept of Arrays.

Matrix Multiplication

Multiplying Matrices
with Each Other.