These are randomly generated values that use the foreground and background colors to make cloud patterns. Applying this filter multiple times will create rib and vein patterns that resemble a marbled texture.

Levels is used to correct the tonal range and the color balance of an image. It does this by adjusting the intensity of the shadows, midtones, and highlights of your image.

With this adjustment layer, you can adjust the hue (color), saturation, and lightness of a specific range of colors in your image.

Blending mode controls how the layer interacts with other layers. For example, the blending mode "multiply" looks at the color of your layer and multiplies the base color by the blend color. The result is always a darker color. Multiplying with black results in black, multiplying with white leaves the color unchanged.