Read about arrays

http://www.snb-vba.eu/VBA_Arrays_en.html

That's what aryPair is



There's really no counting, except for knowing how many pairs of cells are linked (8 in the latest example)

If there are more than 8, then the dimensions for aryPair needs to be updated

The aryPair (x, y) have NOTHING to do with the cell location, address, row, column, or value

The 'x' is a pair counter (1 to 8), and the 'y' (1 to 2) is the two cells that are linked

The linked cells are Set (since aryPair is storing Ranges) so that the Worksheet_Change logic knows what to check

So the 7th pair entry links these two cells on Sheet1 and Sheet2

Set aryPair(7, 1) = ws1.Range("F10") 
Set aryPair(7, 2) = ws2.Range("E12")