In depth analysis of a work. Often found in literary journals, accessible from databases, and in books. Frequently highly focused on a particular aspect of the work.
Plot summaries and a study of major themes and characters. Not as specific or technical as Critical Essays.
Information about the life of the author with special focus on their literary career and major works. These are good sources for discovering the prominent themes and emphasis of a particular author.
A brief article where the writer offers opinion and recommendation about the literary work. These are not usually as technical as a critical essay but some reviews are quite insightful.