A review article synthesizes information from other studies. It does not generate new knowledge but rather gives an idea of the current state of a topic. It will not have a methodology section and can be laid out in several different ways. Literature reviews have subheadings that can be topical, chronological, or methodological, depending on the subject. Review articles will typically be structured like this:
Introduction
Subheading - Topic 1
Subheading - Topic 2
Subheading - Topic 3
Conclusion
The introduction will include:
A very general background introducing your topic
An overview of what the review is about, including its purpose
A problem statement ("Large levels of plastics in the ocean are threatening multiple ecosystems.")
Things to Avoid:
Excessive length
Leaving out the justification for the study
The main body will be the bulk of your paper. It will include information that's arranged sequentially into different sections. Normally that will be either chronologically, thematically, or methodologically, depending on your topic. You will use subheadings for each sections that indicate what that portion will contain. It's extremely helpful to make an outline while you're planning your paper. For example, here is an outline for a paper about Swem Library:
Introduction: What is Swem Library, where is it located, general information about W&M
Main Body
History of Swem
Various buildings
Who Earl Gregg Swem was
What was collected in the past
Current Operations
Current state of collections
Services provided
Importance on campus
Future Directions
The library's strategic plan
Changes in libraries nationwide
Conclusion
Things to avoid:
Listing facts without providing analysis
Sections that are not organized in a logical way
Abrupt changes in between different topics -- a lack of "flow"
The conclusion is where you will restate your major findings, interpretations, and suggest greater significance or future directions. It should be brief, one page at the most, and should recap the results of your analysis.
Things to Avoid:
Introducing large ideas not already covered in the paper
Excessive length -- conclusion should be brief