Short answers, pulled from the story.
Drawing is a visual art that uses an instrument to mark paper or another two-dimensional surface, or a digital representation of such. A drawing instrument releases a small amount of material onto a surface, leaving a visible mark. Traditional instruments include pencils, crayons, and ink pens, while modern tools include computer styluses, graphics tablets, and gamepads in VR drawing software.
Drawing is one of the oldest forms of human expression, with evidence preceding written communication. Cave and rock paintings appeared around 30,000 years ago during the Art of the Upper Paleolithic. These drawings, known as pictograms, depicted objects and abstract concepts and were eventually simplified into proto-writing and early writing systems.
The Quarrel of Color was a seventeenth-century debate that pitted proponents of color against those of drawing. In it, drawing was understood as independent of technique and medium, referring mainly to the contour lines of a subject rather than the colored surface, a distinction famously made by Leonardo da Vinci.
Linear perspective portrays objects so their dimensions shrink with distance, with parallel edges converging at a vanishing point along the horizon. Two-point perspective adds a second vanishing point, and three-point perspective adds a third above or below the horizon. Depth is also created through texture compression, reduced contrast, and less saturated colors that reproduce atmospheric haze.
Drawing became significant as an art form around the late fifteenth century, with engravers such as Albrecht Durer and Martin Schongauer, who lived from around 1448 to 1491 and was the first Northern engraver known by name. In the twentieth century, Pablo Picasso, Andy Warhol, and Jean-Michel Basquiat kept drawing at the center of their practice.
Drawing diagrams of observations is an important part of scientific study and has served as a method of discovery, understanding, and explanation. In 1609, Galileo Galilei used observational telescopic drawings to explain the phases of Venus and sunspots, and in 1924 geophysicist Alfred Wegener used illustrations to demonstrate the origin of the continents.
Studies suggest perception is the most important factor, supported by a robust relationship between perception and drawing ability, which formed the basis of Betty Edwards' book Drawing on the Right Side of the Brain. Motor control plays a role but its effects are not significant, while artists also spend more time on strategic and metacognitive decision-making than non-artists.