Shading is used to create the illusion of depth and dimension on a flat surface by varying the darkness and lightness of areas.

Smudging is not a shading technique but a blending technique used to soften the edges of lines or areas.

Shading refers to the gradual change in darkness or lightness within an area, creating a sense of depth and form. Tone, on the other hand, refers to the overall lightness or darkness of an area, which can be used to create contrast and emphasis.

The color of the light source does not directly affect the tone of an area in a drawing. It primarily affects the hue and saturation of the colors in the drawing.

Cross-hatching is a shading technique that involves creating a series of intersecting lines to create a sense of texture and depth. It is often used to create the illusion of materials such as wood, fabric, or metal.

Radial shading is not a common type of shading used in drawing. It involves creating a series of concentric circles to create a sense of depth and form, but it is less frequently used compared to linear, contour, and value shading.

Stippling is a shading technique that involves creating a series of small dots to create a sense of texture and depth. It is often used to create the illusion of materials such as fur, skin, or grass.

Complementary tone is not a common type of tone used in drawing. It refers to the relationship between two colors that are opposite each other on the color wheel, such as red and green. Complementary tones are often used to create contrast and emphasis in a drawing, but they are not typically used to describe the overall lightness or darkness of an area.

Hatching is a shading technique that involves creating a series of parallel lines to create a sense of texture and depth. It is often used to create the illusion of materials such as wood, fabric, or metal.

Radial shading is not a common type of shading used in drawing. It involves creating a series of concentric circles to create a sense of depth and form, but it is less frequently used compared to linear, contour, and value shading.

Contour shading is a shading technique that involves following the contours of an object to create a sense of depth and form. It is often used to create the illusion of three-dimensionality.

Complementary tone is not a common type of tone used in drawing. It refers to the relationship between two colors that are opposite each other on the color wheel, such as red and green. Complementary tones are often used to create contrast and emphasis in a drawing, but they are not typically used to describe the overall lightness or darkness of an area.

Value shading is a shading technique that involves using different values of lightness and darkness to create a sense of depth and form. It is often used to create the illusion of three-dimensionality.

Radial shading is not a common type of shading used in drawing. It involves creating a series of concentric circles to create a sense of depth and form, but it is less frequently used compared to linear, contour, and value shading.

Linear shading is a shading technique that involves creating a series of parallel lines to create a sense of depth and form. It is often used to create the illusion of three-dimensionality.