In C programming language, a multidimensional array is an array that contains more than one dimension. The most common types of multidimensional arrays are two-dimensional and three-dimensional arrays.

A two-dimensional array is an array of arrays, where each element in the array is an array of elements. Here is an example of how to declare and initialize a 2D array in C:

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int array2D[3][4] = {    {1, 2, 3, 4},    {5, 6, 7, 8},    {9, 10, 11, 12} };

In this example, array2D is a 2D array with 3 rows and 4 columns. The elements of the array can be accessed using the indices of the rows and columns, for example:

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printf("%d", array2D[1][2]);  // Prints 7

A three-dimensional array is an array of arrays of arrays, where each element in the array is an array of arrays. Here is an example of how to declare and initialize a 3D array in C:

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int array3D[2][3][4] = {    {        {1, 2, 3, 4},        {5, 6, 7, 8},        {9, 10, 11, 12}    },    {        {13, 14, 15, 16},        {17, 18, 19, 20},        {21, 22, 23, 24}    } };

In this example, array3D is a 3D array with 2 planes, 3 rows and 4 columns. The elements of the array can be accessed using the indices of the planes, rows and columns, for example:

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printf("%d", array3D[1][2][3]);  // Prints 24

It's important to note that when you declare a multidimensional array, you must specify the size of each dimension, and that the size of the first dimension is the number of elements in the second dimension and so on.