If you select Export, you will see options for exporting the clip:

 

Export Destination: the location to which the clip will be exported. See Folders for more information.

Export Options (select any number, or none): 
 
Copy Auxiliary Files: SRT files containing closed-captioning information will be copied along with the video files, along with some other files such as SmartChapter XML files. 
Create Metadata XML: An XML file containing library information (title, channel, description, etc.)  for the item will be copied along with the video file.
Remove Metadata from File: All Library metadata will be stripped from the file. This is useful for compatibility with certain third-party video editing programs. 
Keep Clip: Retain a copy of the clip in the Library
Upload Thumbnail: Includes a JPEG snapshot of the first frame of the clip

The Description Box is pre-populated with description metadata from the Program Guide for the original recording. You can edit this information to add a custom description to the metadata of the clip. If the Create Metadata XML option is used, this information will be included.