Short answers, pulled from the story.
Literary realism is a movement and genre that attempts to represent mundane, everyday subject matter in a faithful and straightforward way, avoiding exaggeration, supernatural elements, and exotic settings. The movement began as a post-1848 phenomenon, according to its first theorist Jules-Francois Champfleury, with roots in mid-nineteenth-century French literature and Russian literature.
Literary realism seeks to describe subjects as they are, while naturalism, which grew from realism under the influence of Charles Darwin, also attempts to determine the underlying forces of heredity, environment, and social conditions that shape human character. Naturalistic works tend to focus on darker aspects of life, including poverty, violence, and disease, and are often more pessimistic in tone.
Socialist realism was the official Soviet art form institutionalized by Joseph Stalin in 1934, requiring truthful, historically concrete representation of reality in its revolutionary development, linked to the ideological education of workers in the spirit of socialism. The movement had existed since at least the Bolshevik Revolution, but the Statute of the Union of Soviet Writers in 1934 gave it its canonical formulation.
William Dean Howells, born in 1837, was the first American author to bring a realist aesthetic to United States literature. Mark Twain, Stephen Crane, and later John Steinbeck, Theodore Dreiser, Edith Wharton, and Henry James are among the major American realists. Crane's The Red Badge of Courage was published to great acclaim in 1895, and Maggie: A Girl of the Streets in 1893 is considered one of the earliest naturalistic American novels.
Verismo was an Italian literary movement whose main representatives were Giovanni Verga and Luigi Capuana. Unlike French naturalism, which believed literature could influence society and whose authors inserted moral commentary into their works, Verist authors believed reality could not be changed through literature and deliberately distanced themselves from the narration, adopting an objective, non-intrusive perspective. Grazia Deledda, associated with the movement, won the Nobel Prize for Literature in 1926.
Kitchen sink realism is a British cultural movement that developed in the late 1950s and early 1960s in theatre, film, novels, and television, depicting working-class Britons in cramped rented accommodation and exploring social and political issues. John Osborne's Look Back in Anger in 1956 is considered the first work of the genre, set in a one-room flat in the English Midlands. The conventions persisted into television series such as Coronation Street and EastEnders.