Style in drawing is a collection of attributes that make drawings unique. Each period in the history of art is characterized by the style of some groundbreaking artists. For example, modernism is characterized in part by Cubism, a style developed by Pablo Picasso and Georges Braque.
Here are common drawing styles:
Abstraction/Nonrepresentational: Artists who work in an abstract style make drawings that are usually about shape, line, value, color, and/or texture. Practitioners of the nonrepresentational style of drawing include Piet Mondrian, Joseph Albers, and Al Held.
Art Nouveau: Artists who work in an Art Nouveau style make drawings that are illusionistic but primarily flat, that are highly pattern driven, and that usually incorporate fluid, curving lines. Practitioners of Art Nouveau include Gustave Klimt, Aubrey Beardsley, and Alphonse Mucha.
Manga: Artists who practice the Manga style make drawings based on the Japanese comic book style developed in 19th Century Japan. Practitioners of Manga include Osamu Tezuka and Machiko Hasegawa.
Post-impressionism: Artists who practiced the style called post-impressionism made drawings based on light (the preoccupation of the impressionists) but with more attention to geometric shapes. This style includes some purposefully expressive distortions. Practitioners of post-impressionism include Georges Seurat, Paul Cezanne, and Vincent VanGogh.
Realism: When artists draw convincing representations of reality, the style is called realism. Practitioners of realism include Leonardo Da Vinci, Jean Augustus Dominique Ingres, William Beckman, and Steven Assael.
Surrealism: Artists who draw dreamlike and sometimes startling works based on pure imagination are practicing surrealism. Practitioners of surrealism include Salvador Dali, Marcel Duchamp, and Yves Tanguy.