Highlight column differences

Generic formula 

=$A1<>$B1

Summary 

If you want to highlight the differences between two columns of data with conditional formatting you can do so with a simple formula that uses the" not equal to" operator (e.g. <>) and mixed references.

For example, if you have similar data in B2:B11 and C2:C11, and you want to highlight cells where values differ, select the data in both columns, starting from B2, and use this formula:

=$B2<>$C2

A case sensitive option

By the "equals to" and "not equals to" operators (= and <>) are not case-sensitive. If you need a case-sensitive comparison, you can use the EXACT function with NOT, like so:

=NOT(EXACT($B2,$C2))