Take C language as an example. It has the same definition as a one-dimensional array, and there is no difference:

int a[ 10][ 10]； //Define an integer array of 10x 10.

char b[20][20]； //Define a 20x20 character array.

handkerchief

Variable a: an integer of the array [0.. 10,0.. 10];

Variable b: char of array [0 ... 20, 0 ... 20]