Literary criticism is the study, evaluation, and interpretation of literature. Modern literary criticism is often informed by literary theory, which is the philosophical discussion of its methods and goals. Though the two activities are closely related, literary critics are not always, and have not always been, theorists.
Whether or not literary criticism should be considered a separate field of inquiry from literary theory, or conversely from book reviewing, is a matter of some controversy. For example, the Johns Hopkins Guide to Literary Theory and Criticism draws no distinction between literary theory and literary criticism, and almost always uses the terms together to describe the same concept. Some critics consider literary criticism a practical application of literary theory, because criticism always deals directly with particular literary works, while theory may be more general or abstract.
Literary criticism is often published in essay or book form. Academic literary critics teach in literature departments and publish in academic journals, and more popular critics publish their criticism in broadly circulating periodicals such as the Times Literary Supplement, the New York Times Book Review, the New York Review of Books, the London Review of Books, The Nation, and The New Yorker.