I have two columns where I want to highlight differences 
I want to see if the letter in Column A exists in Column B - it should be case-sensitive, because there are C and c in column A
If there is a match I want the row preferably turn green - otherwise a OK / NOT OK in column C
Thank you in advance

Excel 2016 - compare two columns for match
Copy this Sub to the Worksheet code pane. For this open the Developer tab and click Visual Basic. In the left pane select the worksheet where your datas are, and doubleclick it. Insert the code.
Private Sub Worksheet_Change(ByVal Target As Excel.Range)
If Target.Column = 1 And InStr(1, Target.Offset(0, 1).Value, Target.Value) > 0 Then
Target.EntireRow.Interior.Color = vbGreen
Else
Target.EntireRow.Interior.ColorIndex = xlColorIndexNone
End If
If Target.Column = 2 Then
If InStr(1, Target.Value, Target.Offset(0, -1)) > 0 Then
Target.EntireRow.Interior.Color = vbGreen
Else
Target.EntireRow.Interior.ColorIndex = xlColorIndexNone
End If
End If
End Sub


If the content change in column A or B the respective row color will change.
