Here, you can choose which media libraries included in the import package will be imported. The following extra options can be adjusted:
•Import media files - if checked, media files (stored in database) included in the package will be imported together with the media libraries. If you are importing to an existing site, this option is de-selected by default.
•Import physical files - if checked, physical files (stored in the file system) included in the package will be imported together with the media libraries.
Detailed information about the built-in export/import functionality in Kentico CMS can be found in Developer's Guide -> Managing sites -> Export and import.