For a video tour of what is available from Wesleyan's library, see the library website overview.
OneSearch covers most, but not quite all, of Wesleyan library’s online and physical resources, including the library collections at Wesleyan (and also at Trinity and Conn College) and most of the indexes and databases the library subscribes to. It does not search WorldCat.
WorldCat is a list of most books in most libraries in the United States and many libraries elsewhere, so if a book has been published and cataloged by libraries it is most likely listed in WorldCat. This includes many titles not in Wesleyan’s collection and thus not included in Library OneSearch. WorldCat does indicate whether a particular title is held by Wesleyan, Trinity, or Conn College.
So, if you are looking for a specific book (or audio/video recording or other specific known item), use OneSearch to find whether it is available at Wesleyan, Trinity, or Conn College. For books not available at a CTW library, you can use WorldCat, which allows you to place an interlibrary loan request for it.
If you are looking for a specific article, use the Journal Locator to see whether Wesleyan has online access or a physical copy of the journal, then find the article in the journal. If the library does not subscribe to the journal, you can place an interlibrary loan request for the article. Or, you can enter the article title into OneSearch to see if OneSearch has a record for the article -- to make sure the record for the article shows up at or near the top of the results list, put quotes around the title to search it as a phrase, and add the author's name and/or the title of the journal.
If you are looking for information on a topic, OneSearch is a good place to start. Enter a few keywords to describe your topic, then you can narrow and specify the results using the facets on the left of the screen (limiting to peer reviewed sources, sources in a particular discipline, reference sources, etc). Or, you can look through the Indexes & Databases to find an appropriate subject specific index of publications.