A two-dimensional array has two subscripts to identify each element.

Example:

The three monthly sales totals for six salesmen are set up in a two-dimensional array called 'SALES'.

There are 6 rows and 3 columns. 
(The grey headings are not part of the array - they are headings for us to understand the meaning of the array)

SALES[2,1] would be '£650' (Row 3, Column 2).