A literature review is a section of a scholarly article or book (usually toward the begining) which summarizes and evaluates previous scholarship.
The purpose of a literature review is to give an accurate and complete accounting of the current state of knowledge for whichever research question you are attempting to answer. It is an essential feature of scholarship because without it the reader cannot judge how well-informed you are or how original your approach might be.
What you end up writing will be probably be different in two ways.
1) You should have a much narrower focus. These attempt to cover very broad topics.
2) You should delve back a number of years to learn everything you can about your topic. These only try to account for what has happened over the last year.