A comment on a daily record gives details about why that student is considered absent/tardy/etc. for the entire school day. A student can have only one daily attendance record per day. You can comment on daily attendance records directly on the Daily Attendance page or on student pages.
Comments left on daily attendance records display as a tooltip on the Class Attendance page, and can be seen on the Daily Attendance Page, on the Analysis page, and the student page.
Daily Attendance Page
It's most common and efficient to comment on daily records as you log them. Use the "Comments" box on the Daily Attendance page.
You can also update daily attendance records, including their comments, in the list of records on the lower part of the page. Click the pencil icon and add/edit the comment as needed.
You can add and edit comments on daily attendance records on the student page as well. Click into the "Daily Attendance" tab and then click the pencil icon next to a record, just as in the .gif above.