That only cycles through open windows for the current in-focus application.
E.g. If I have 2 Excelsheets open and 2 Word documents open, if Word is the current in-focus app ... CMD+` only cycles between the 2 Words documents (and does not cycle the Excel sheets)
E.g. If I have 2 Excelsheets open and 2 Word documents open, if Word is the current in-focus app ... CMD+` only cycles between the 2 Words documents (and does not cycle the Excel sheets)