A library catalogue lists the resources you will find in the library's collections.
An online catalogue is called an OPAC. This stands for Online Public Access Catalogue. It allows you to search for information in many ways, including by author, title, subject and keyword.
The library catalogue is always a good place to start a search.
A bibliography is usually a list of works written by a particular author or about a particular subject. A bibliography, or reference list, is how you acknowledge the author's work you have used to write an essay or an assignment.
An index is an alphabetically arranged list of the headings or topics that appear in a published work. An index will also provide page numbers that point to the area of the work that you need to go to