A 2D array in C is an array of arrays. It is a data structure that represents a table-like structure with rows and columns. Each element in the 2D array is accessed using two indices: the row index and the column index. Here is an example of declaring and initializing a 2D array in C: #include int main() { int arr[3][4] = { {1, 2, 3, 4}, {5, 6, 7, 8}, {9, 10, 11, 12} }; // Accessing elements in the 2D array printf("%d\n", arr[0][0]); // Output: 1 printf("%d\n", arr[1][2]); // Output: 7 printf("%d\n", arr[2][3]); // Output: 12 return 0; } In this example, we declare a 2D array `arr` with 3 rows and 4 columns. We initialize it with some values using the initializer list. The indexing starts from 0, so `arr[0][0]` refers to the first element in the array, `arr[1][2]` refers to the element in the second row and third column, and `arr[2][3]` refers to the element in the third row and fourth column. Note that the size of each dimension of the 2D array must be specified at the time of declaration.