Arrays: A collection of elements of the same type, stored in contiguous memory locations. Used to store fixed-size sequential elements.
Example:

int[] arr = {1, 2, 3, 4, 5};
for (int i : arr) {
 System.out.println(i);
}
System.out.println("Length: " + arr.length);

Multi-Dimensional Arrays:

int[][] matrix = {{1, 2}, {3, 4}, {5, 6}};
for (int[] row : matrix) {
 for (int col : row) {
 System.out.print(col + " ");
 }
 System.out.println();
}