Java specifies arrays similar to that of a “row major” configuration, meaning that it indexes rows first. This is because a 2D array is an “array of arrays”.
For example:
int[ ][ ] a = new int[2][4]; // Two rows and four columns.
a[0][0] a[0][1] a[0][2] a[0][3]
a[1][0] a[1][1] a[1][2] a[1][3]
It can also be visualized more like this:
a[0] -> [0] [1] [2] [3]
a[1] -> [0] [1] [2] [3]
The second illustration shows the “array of arrays” aspect. The first array contains {a[0] and a[1]}, and each of those is an array containing four elements, {[0][1][2][3]}.
TL;DR summary:
Array[number of arrays][how many elements in each of those arrays]
For more explanations, see also Arrays – 2-dimensional.