If you are starting research on a topic or issue that is unfamiliar to you, a fast and easy way to build basic familiarity is to consult a resource that provides an overview of the topic or issue. An overview can inform you about different aspects of a topic and provide you with ideas about how to narrow or broaden your research focus. An overview may also introduce you to new vocabulary and key resources to help build your keyword lists. There are a number of excellent resources in Medicine, Nursing, and Allied Health.
Specialized online encyclopedias can provide you with a quick, basic overview.