Uses the Media Library Assistant plugin.
Select Media > Att. Categories to add a new category. Complete the Name and select Add New Att. Category (in blue).
The new category will now appear on the right-hand side.
Images in your Media Library can now be edited to be associated with this category.
Tags can be added to the image information as well.
Now you have added the tag and category information it’s possible to search within your Media Library by category or tag.
You can upload multiple images to a category by selecting Media > Add New in the left-hand admin menu and then selecting Open Bulk Edit area.
Select the tick box on the left at the bottom for the appropriate category before clicking the Select Files button.