Hi there,
I would like to inform you that a file with the ABR file extension is a Photoshop Brush file that stores information about the shape and texture of one or more brushes. They're used through Photoshop's Brush tool. The location of the files stored in Users/User Name/Library/Application Support/Adobe/Adobe Photoshop version/Presets/Brushes in Mac.
If you’d like to add a bundle of .abr files at the same time, you can drop them directly into Photoshop’s Brushes folder. Make sure the program is closed, and then use Mac Finder to locate the Adobe Photoshop folder. Once you’ve located the Adobe Photoshop folder, click “Presets” and then “Brushes”. Here, you’ll find all of Photoshop’s current brush presets. Just highlight and drag them into the folder. When you open Photoshop, you’ll see all of the new brushes in the preset menu.
You may click on this link for more information: https://helpx.adobe.com/photoshop/using/brush-presets.html
Let us know if that helps.
Regards,
Tarun