Here, you can select which inline controls included in the import package will be imported. If you are importing from an older version of Kentico CMS, a warning is displayed, so that you are careful not to overwrite physical files with the old ones from the previous version.
Detailed information about the built-in export/import functionality in Kentico CMS can be found in Developer's Guide -> Managing sites -> Export and import.
Page url: http://devnet.kentico.com/docs/6_0/contexthelp/index.html?importgrid_cms_inlinecontrol.htm