All media files, such as images, video, audio and documents from your own computer or other sources that you’ve ever uploaded to posts or pages are listed in your media library. Once you upload an item, it remains in the the media library for you to edit or insert into your page or post.
Your media library displays all types files. You can choose to view images only, audio only or video only by clicking on the link. You can filter media types by date or search media files using specific keywords.
Hovering your mouse over a file name brings up the Edit, Permanently Delete, and View action links below the title.
Once Media is uploaded, the information associated with that Media can be edited. To do so, open Edit Media window as shown below.
Image provided by WordPress.org
Enter the Title of this Media. The Title will displayed in the File column of the Media Library Screen.
Enter the Alt text for the image, e.g. “The Mona Lisa”.
The caption for this Media. For image type Media, the Caption is also used as alternate text for that image.
A description for this particular Media.
Enter the physical location of the uploaded file.
Click the Save all changes to save the Media. At that point the Media Library Screen is displayed.
Clicking the action link Permanently Deletes removes that file from your site and deletes it. Be careful! Once deleted you can’t undelete a file.
If the file you delete was in a post or page, it will no longer be available for your readers. For example, if you delete an image that is being used in a post then the image will no longer display in the post.
Clicking the action link View opens up the file in a post on your blog.