What is a literature review?

At one point in your academic journey, you will probably have to do what is called a "literature review" or "review of literature".

This can be an assignment for your course. You then need to gather a few documents on a specific subject and compare them to one another.
Usually, you're not going to analyse them one by one (that would be called an annotated bibliography), but you need to analyse their content to create a report based on various common themes you've identified.

A literature review is also an important part of a thesis or dissertation, of which it will often form a full chapter.
In it, you analyse what has been published on your research topic, trying to spot lacks in the research, and any kind of information that will help you with your own research (i.e.: this particular methodology doesn't seem very reliable, this kind of test is best used on preschoolers, etc.).
Your literature review can also provide an historical background and an overview of the current context in which your research is situated. It will introduce relevant terminology and provide definitions.

Each information you write in a literature review (except for your own views) needs to be properly cited.

To complete a literature review, here is an overview of the process you need to go through:
1. Define your topic.
2. Identify relevant documents through a literature search.
3. Read the documents while taking thorough notes.
4. Analyse the documents to come up with the plan for your review.
5. Write your review while citing all the documents accurately.
6. In your conclusion, mention how your findings will affect your research project.

For more details, check The Literature Review, 2nd Edition, by Diana Ridley (on the "new books" shelf).

You could also have a look at this presentation and these links.

Or ask your tutor to organise a training session with me on this topic!