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There are 3 types of behaviour which can be set by using Class Rollover Action. 
- An A class set to "Archive" class remains visible will remain visible to staff and students on the current session but year (which will become last years tab e.g. 2014/15) but is is not available to staff and students on the next session (e.g. 2015/16).
Generally this will be used when a class is no longer continuing in it's current form but current students may need to access it in the future for reference. - A class set to "Rollover" class is copied to will be result in a 'clean' class in the next session , remains visible to staff and students (e.g. 2015/16), last years class will exist on the current session, content is reset for the next session and hidden to students on the next session.
The years session (which will become last years tab e.g. 2014/15).
This is the most common setting, this will remove all student information but leave the class content intact for the next year's enrolment of students. Students who attended this class in previous years will still be able to access their assignments (if unrestricted) in the class on the previous years tab. - A "Move" class is copied to the next session, is hidden to staff and students on the current session, and is visible to staff and students on the next session.
This setting allows for a course to run over 2 or more years with the same group of students, retaining all their information.
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