What is the difference between Opacity and Fill in the Layers panel?

• A. Opacity affects the entire layer and its effects; Fill affects only the layer's pixels, leaving layer styles visible.
• B. Opacity affects only the pixels; Fill affects the entire layer.
• C. Opacity changes the blend mode; Fill changes the hue.
• D. Opacity is for vector layers; Fill is for raster layers.

Answer: (A)

Opacity controls how transparent the entire layer appears, including anything applied to the layer as effects. Fill, on the other hand, only affects the layer’s actual pixels—the visible content—while leaving any layer styles (like shadows, strokes, outer glow) visible even when the content itself is largely transparent. So if you drop Fill to 0%, the text or image content vanishes but the layer styles stay shown; if you reduce Opacity, both the content and the layer styles fade together. This distinction is what makes the statement the best description of how these two controls behave.