Indicating mismatches in 2 columns

I have 2 columns, first one is the IDs of students for Q1, the second one is the IDs of students for Q2. In the Q2 new students were accepted and some students dropped, so there is a mismatch in the list of IDs. I need a function that will indicate those IDs that are present in column A but are not included in Column B and vise versa.

Thank you!

Hi,

Welcome to the Forum.

I have highlighted the cells which are not in the other column & vice versa in RED in the attached sample file using "Conditional Formatting". See if this is what you are looking for.

This is exactly what I am looking for
Can you please explain step by step how you did it?
Thanks in advance

Keep the cursor in A2:

Conditional Formatting -> New Rule -> Use a Formula to determine which cells to format -> enter the below formula in the formula bar -> choose the appropriate background color / Text Color -> Ok

=COUNTIF(B:B,$A2)<1