Clipping Mask for a Product Image

You do need to ask them exactly what they want, because the exact term “clipping mask” is not a thing that’s typically delivered to a client. There are three very similarly named features in Photoshop, and this is why you need to clarify it with them:

A clipping mask is what Myra described: A way to make one layer mask another layer. But this is not something you would typically be asked to deliver, it’s just a way of getting a certain effect.

A layer pixel or vector mask is more likely, because you can use it to make the background transparent, after using an appropriate selection tool to isolate the subject.

But I am wondering if you are being told to create a clipping path, not clipping mask. A clipping path is a traditional background cut-out method used for over 30 years to remove backgrounds from product artwork. A clipping path requires these steps, shown in the photo below:

1. Isolate the subject outline using a vector path. (Not a vector shape layer.) This can be done by drawing or tracing the subject’s outline using any path tool. But you can also use any pixel selection method such as the Object Selection tool, and then you can convert that to the required path (that is how I created my quick and sloppy path in the picture, you’ll want to clean it up more than I did). 

2. The path must be assigned as a Clipping Path using the command shown in the Paths panel menu below. 

3. The image must be saved in a file format that supports clipping paths, such as TIFF.  

Because this is a product photo, my guess is they really want you to create a clipping path. That is what you should confirm.

You should ask them what exactly they want.

If they want you to remove the background, they might mean layer mask instead of a clipping mask. You can use the Object Selection tool to select the DVD, and in the Layers panel, click the 3rd icon at the bottom of the panel to convert the selection in to a layer mask.

If they want the masked shape to be used for other DVD covers, then once the shape is masked, another layer can be placed above it. Then you can select the top layer, right-click, and select Create Clipping Mask. That layer's contents will then become masked by the shape of the DVD below it.