A clipping mask in Photoshop allows you to use a layer to mask the content of another layer. The content of the lower layer is only visible where the upper layer, the mask, is opaque. Here's how you can add a clipping mask in Photoshop:
Create two layers, one for the content and one for the mask. The content layer should be placed below the mask layer in the Layers panel.
Select the content layer by clicking on it in the Layers panel.
Hold down the Alt (Option) key and click between the two layers in the Layers panel. This creates a clipping mask and links the two layers.
The mask layer will now act as a mask for the content layer, hiding any content that falls outside of the mask. You can edit the mask by painting on it with black or white to control the opacity of the content layer.
Note: Clipping masks can also be created between a layer and a vector shape or text layer, allowing you to use shapes or text as masks. To do this, simply follow the same steps as above, but select the vector shape or text layer as the mask instead of a raster layer.
