Reference sources, or academic encyclopedias, will provide you with larger context for your research.
What is reference?
A reference collection is a set of books, databases and other items that provide background information on a topic.
Why use reference?
To gather background information that provides context, history and insight into issues related to your subject.
To get a sense of key concepts and terminology.
To gather key words (or keywords) you can use to search for relevant source material on the subject.
This sample article on the neighborhood issue of gentrification illustrates how useful reference articles can be. A small excerpt contains competing definitions of the term and a list of associated problems. This information would provide useful support and context to an essay on rapidly rising housing costs in King County and beyond.