The vanishing point is the point on the horizon where all parallel lines converge. This is because, as lines get further away from the viewer, they appear to come closer together until they eventually meet at a single point.

One-point perspective is used when all lines in the scene converge to a single vanishing point. Two-point perspective is used when there are two vanishing points, one for each set of parallel lines. Three-point perspective is used when there are three vanishing points, one for each set of parallel lines.

In one-point perspective, all parallel lines converge to a single vanishing point on the horizon. This is because the viewer is looking directly at the scene, so all lines appear to recede away from the viewer in a straight line.

In two-point perspective, there are two vanishing points, one for each set of parallel lines. This is because the viewer is looking at the scene from an angle, so the lines appear to recede away from the viewer in two directions.

In three-point perspective, there are three vanishing points, one for each set of parallel lines. This is because the viewer is looking at the scene from below or above, so the lines appear to recede away from the viewer in three directions.

The horizon line is the line that represents the level of the viewer's eye. This is because the viewer is looking at the scene from a fixed point, so the horizon line is always at the same level.

The picture plane is the flat surface on which the drawing is made. This is because the drawing is a two-dimensional representation of a three-dimensional scene, so the picture plane is used to create the illusion of depth.

Orthogonal lines are lines that are perpendicular to the picture plane. This is because orthogonal lines appear to recede away from the viewer in a straight line, so they are used to create the illusion of depth.

Receding lines are lines that converge to a vanishing point. This is because receding lines appear to get smaller as they get further away from the viewer, so they are used to create the illusion of depth.

The size of an object in a perspective drawing depends on its distance from the viewer. This is because objects that are closer to the viewer appear larger than objects that are further away from the viewer.

The shape of an object in a perspective drawing can be distorted by its distance from the viewer. This is because the shape of an object changes as it gets further away from the viewer.

Atmospheric perspective is the technique of using color and value to create the illusion of depth in a drawing. This is because the color and value of an object change as it gets further away from the viewer.

Linear perspective is the technique of using lines to create the illusion of depth in a drawing. This is because lines can be used to create the illusion of receding space.

Aerial perspective is the technique of using color and value to create the illusion of depth in a drawing. This is because the color and value of an object change as it gets further away from the viewer.

Foreshortening is the technique of exaggerating the length of an object in a drawing to create the illusion of depth. This is because objects that are closer to the viewer appear longer than objects that are further away from the viewer.