This section is the beginning of the article, but don’t expect it to contain any sort of position or argument. In academic articles, this section has one, overarching purpose: to demonstrate that the authors are familiar with all previous relevant research on the issue they are writing about. Therefore, this section is usually the most “citation-heavy” section of the paper. It is not uncommon to have one or more citations at the end of each sentence. You will likely also encounter a number of compound citations: parentheticals in which not one source, but two or more are cited at one time. Each sentence that precedes a citation in this section is typically a very brief paraphrase of the relevant methods or applicable findings of the other articles that have come before. This review of prior studies is a very important exercise for scholars because it demonstrates the depth of their understanding. None of the articles you read occur in a vacuum; they are usually part of an evolving web of scholarship. Each new article picks up the thread (or, usually, several threads) left by articles published recently. Another important thing to realize is that, in a very real sense, the authors have not really begun; they do not make an argument or say much that is new in this section. It is designed to provide an academic history and theoretical context for the topic of discussion.
At the very end of every literature review section, however, the authors do something important. After having demonstrated their familiarity with previous research, authors indicate that, even though much research has been done, there are still gaps in the research that need filling. You should try to find language such as, “While many studies have examined this subject, no one has looked at this particular issue in this way.” The authors then announce their intention to address that gap in knowledge with the research that follows. This rhetorical move always appears at the end of this section, and often gives the reader the clearest and most detailed description of what exactly the authors are looking at—and why. This is not a thesis, however. Academic articles are not like the essays you may be used to writing, in which the thesis appears at the end of the introduction. The research gap is more akin to a hypothesis than a thesis. It does not make an argument, which comes much later—usually in the discussion or conclusion.
There are also articles that are stand-alone literature reviews; these are sometimes called “Review Articles” or “Meta-analyses.” Rather than engaging in original research, these articles, if they are recent and on point, can provide you with the bibliographic information of all the important, recent sources on your topic. There are many ways to find sources that don’t involve a search engine of any kind. Look at your articles’ references lists to see if they contain any relevant-sounding articles that you haven’t found by other means. You can save a great deal of time this way.