A bibliography is a list of writings by an author, such as the lengthy bibliography of Joyce Carol Oates, or a list of writings someone uses in a project, like the bibliography at the end of a research paper.
Bibliography comes from the Greek word biblio, or "book," and graphos, which is "something written or drawn." So, a bibliography is made when someone writes a list of books or other written works. You may have included a bibliography with a research paper you have written, to give credit to your sources. However, due to the popularity of using internet sources instead of books these days, some writers prefer "Works Cited" over "Bibliography."