=AND($A1<>",$A1<>$A2)

[Rob R]

Can someone translate this formula to English?

thanks in advance

 

[Frank Kabel]

Hi
probably a small typo. Should read
=AND($A1<>"",$A1<>$A2)

checks that A1 is not empty and is not equal to the next cell in A2

 

[Bob Phillips]

It is saying

test for A1 not containing no data, and also if A1 not equals the value
below. If both conditions are met it returns TRUE, if one or both is not met
it returns FALSE. These can be used in conditional formatting to determine
whether the format is set or not.

This was used in your case to find the last item is a series of like items,
to highlight them.