The oldest form of literary criticism, called traditional criticism, evaluates literature in terms of its historical context, allusions in the text and influence. A given piece of literature is analyzed in terms of its author's biography, social impact, engagement with other literary classics or ideas and other pieces of literature by the same author. These factors external of the text help literary critics situate the text within a larger scope.
Formalism is concerned with the elements of a piece of literature's construction. This type of criticism evaluates a work aside from the author's biography or other external factors. It seeks to evaluate literature in terms of its literary components within the text. New criticism also divorces a text's context with its internal features. It seeks to remove any historical or personal context to a work and evaluate the work's internal features, such as rhyme, meter, metaphor, rhythm or diction. Some critics draw a distinction between new criticism and formalism while others argue that new criticism is a form of formalism.
Because literature has expanded to include entertainment, advertising, publishing, television, film, computers and the Internet, many academics felt a new type of literary criticism was needed to evaluate these modern forms of text. As a result, cultural studies developed in the 1990s, and it refers to a study of a text from a certain cultural perspective. Feminism, media studies, philosophy of language, queer theory, gender studies and Marxism can all be considered realms of cultural studies. Cultural studies takes one of these hermeneutics, or modes of interpretation, and uses it to evaluate ideas and techniques in a text.
Postmodern criticism seeks to evaluate the points at which a system of words and meanings breaks down. Postmodernists, also called Deconstructionists, think there is no one meaning to a text. Rather, there are many complimentary and contradictory meanings and ideas within a text, and the way to evaluate a text is to take apart its constructions, or systems of arrangement. In other words, a text does not work as a whole, but it is comprised of many parts that contribute to the whole in unique ways.