What does a Layer Mask do in Photoshop?

What does a Layer Mask do in Photoshop?

• A. A Layer Mask hides parts of a layer with red paint.
• B. A Layer Mask permanently deletes pixels.
• C. A Layer Mask hides or reveals parts of a layer without deleting pixels; painting with black hides, white reveals.
• D. A Layer Mask changes the layer's color mode.

Answer: (C)

Layer masks give you a non-destructive way to control visibility of a layer. The mask is a grayscale channel: white areas let the layer show through, black areas hide it, and gray areas create partial transparency. Because the pixels themselves aren’t erased or deleted, you can adjust or remove the mask later to reveal more detail. This is why the description that emphasizes hiding or revealing parts of a layer without deleting pixels—and notes that black hides and white reveals—is the best fit. Painting with red or any color isn’t how masks work, since masks rely on grayscale values to control transparency, not color. Changing a layer’s color mode is a different operation altogether.

Layer masks give you a non-destructive way to control visibility of a layer. The mask is a grayscale channel: white areas let the layer show through, black areas hide it, and gray areas create partial transparency. Because the pixels themselves aren’t erased or deleted, you can adjust or remove the mask later to reveal more detail. This is why the description that emphasizes hiding or revealing parts of a layer without deleting pixels—and notes that black hides and white reveals—is the best fit. Painting with red or any color isn’t how masks work, since masks rely on grayscale values to control transparency, not color. Changing a layer’s color mode is a different operation altogether.