In literary studies Formalism is the study of literary forms (e.g., metaphors, symbols, narrative) as distinct from literary history or cultural movements (e.g. early American literature, Modernism) or special-interest, thematic, or multicultural studies (e.g., women's literature, science fiction, African American literature).
If Historicism emphasizes the reality that texts represent, Formalism studies the techniques by which writers represent whatever reality that constitutes their subject.
The "forms" that Formalism studies vary.
Any of these levels may emphasize less a particular unchanging form and more how different forms adapt to, describe, or embody new forms of experience.
Formalism has a pervasive but often unspoken presence in literary studies.
Formalism is taught in early stages of literary studies, maybe 8th & 9th grades. As students advance, expectations are that they'll already know how to use terms like symbols, meter, etc.
But only a few students per classroom may care or learn about literary forms.
Increasingly literature, especially American literature as taught to Americans, is studied historically.
Why the rejection of Formalism?
Since 1970s, formalism as New Criticism increasingly displaced by more exotic or politicized interpretive methods.
Changes since 1970s means that excessive claims of formalism have relaxed, allowing it to mix with other theories or interpretations,