Presearch is a casual expression used among librarians and other smart people to describe a process of preliminary fact-finding, questioning and answering, topic formation, and genuine exploration of a topic.
Presearch may be necessary to:
Orient yourself with key terminology
Learn important names, events, etc. that are critical to the development of the phenomena in question
Ask secondary questions to deepen your understanding of a topic
The distinction between presearch and research is not necessarily a clear one, as many of the questions you pose and the sources you consult during presearch may very well wind up in your final research project.