Arrays are fixed-size objects with zero-based indexing.

int[] values = new int[3];
values[0] = 10;

int[] scores = {90, 80, 95};

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

Java's multidimensional arrays are arrays of arrays, so rows can have different lengths. Arrays are efficient for indexed access, but collections are usually better when size or data-structure semantics vary.