The Course Short Description appears in the Featured Items area of your Public Site.
The Long Course Description appears in the Full Description areas of your Public Site.
Additional Course Information appears on printed invoices and email confirmations, and on your Public Site. Additional Class Information appears in the Full Description areas of your Public Site and is available in the Course Catalog Report as Class Notes and Materials.
Note: if you add/remove or edit additional course information for a course, the change will be made only to the course additional information, not to the additional information fields for the classes that were built from the course. If you make any new classes from the course with the edited additional information, the edited text will be reflected in the new classes, but any existing classes from this course will retain whatever additional information it has/doesn't have until you change the additional information in the class details page for each class built from that course.