College-level research requires that we use scholarly, reliable, accurate, and current information to support our claims, arguments, and opinions. In addition, not many free web resources can promise that the information they provide is as accurate as an encyclopedia edited and written by experts and published by Oxford, Cambridge, Yale, etc.
Any books that are used to look up background information, facts, the spelling of a word or its meaning, and so forth are reference resources. The Oboler Library has a large reference collection in print, located on the first floor of the building. You also have access to a great many of these kinds of resources electronically, by using our library catalog, OneSearch, or through one of the reference database "packages" like Oxford Reference Online or Gale Virtual Reference Library.