Skip to Main Content

Glossary of Library Terms: D

Library words explained briefly with French translation. Indexes for direct links.


A collection of organized information that can be searched online. Several types of databases can be found in the library: articles, ebooks, reference works and the library catalogue.

An article database is a collection of articles from scholarly journals, magazines, newspapers, reports, etc. It allows you to search through thousands of articles to find information on a particular topic. The ebook and reference works databases allow you to search across and inside a large number of books online. The library catalogue is a database of records that describe each item in the library and provides a call number for you to locate them.

Direct link



base de données


An official term that has been selected by specialists to describe the content of a publication (book, article, report, etc). Also known as a subject term or a subject heading.

Subject descriptors are found in many databases. The specialist will look through a predetermined list of  terms to find the best one for each item. This results in articles on the same topic being grouped together. You can quickly find items that discuss your research topic even when authors are using different terminology. 

Example: One author uses the terms “academic success” and a second author uses “educational achievement”. By using the subject descriptor “academic achievement”, you will retrieve both items.  

The subject terms are usually listed in the database’s thesaurus.

For more examples of using descriptors see UnlockingResearch / Subject Headings.

Direct link




Dewey Decimal Classification

Dewey Decimal Classification (DDC) system is used to assign a series of numbers (a call number) to an item. The call number determines where a book is located on the library shelf and allows for the books to be grouped by subject.

The Dewey Decimal system is most often used in public and school libraries. 

Direct link


                                            classification décimale Dewey


The DOI (Digital Object Identifier) is a string of characters that provides a persistent link to the online location of an article.

Each article is assigned a unique DOI. It can be found on the first page of an article or, if using a database, in the article description. If you don’t see the DOI for your article you can try searching for it here: Not all articles have a DOI.

Examples of a DOI:



Direct link



système DOI     (identificateur d'objets numeriques)