Hovering over a row reveals action links: Edit, Delete Permanently, and View. Clicking Edit or on the media file’s name displays a simple screen to edit that individual file’s metadata. Clicking Delete Permanently will delete the file from the media library (as well as from any posts to which it is currently attached). View will take you to the display page for that file.
Available Actions
For more information:
Documentation on Media Library
Support Forums
Attaching Files