Backup/Restore vs. Import
Backup and Restore
Use Backup and Restore to move course content from one site to another (e.g. from the development area to the live site).
Use Import to move content from one of your courses to another on the same site (e.g. to copy an activity, resource or label from one section to another).
The import function works the same way "restore-adding data to it" works. Weekly or topic summaries are only copied into sections where there is no existing data (i.e topic or weekly summaries in the destination course will not be overwritten).