You have probably noticed that most libraries have a separate section of the building devoted to reference sources and services. But have you ever been told what makes those books special or causes them to be treated differently? Reference sources are authoritative works that help you locate information about people, facts, and ideas. These sources can help you find the date of an important event, major achievements of an individual or organization, or a definition of a term or concept. These are often used to find specific facts, rather than written to be read cover-to-cover, so they are often held in a special part of the library to be used for a short period of time rather than checked out to a user over a period of days.
Reference sources are typically used in many different ways. One use is to get background information on a topic that you are researching. For example, if you use Wikipedia to find out the general history of an event you will be writing about, you are using Wikipedia as a reference source to find out the context of the topic you are researching. This is not information that you’ll paraphrase, quote, or need to cite in your work, as the research you are doing at this point in the process is more to help you learn what information you’ll need to find along the way. Library-owned reference sources often provide this same type of information, but often in academic sources and with a higher level of reliability.
There are many types of reference sources, including dictionaries, encyclopedias, thesauri, directories, and almanacs. More broadly, reference sources can also include bibliographies, manuals, handbooks, atlases, and gazetteers. You can find these resources in print and online.
In learning English at least, we use dictionary, thesaurus and glossary. Dictionaries are like encyclopedias, but instead of providing a contextual background to a subject, a dictionary list terms in alphabetical order and gives each word’s meaning. Some dictionaries include equivalent words in another language, such as an English to Indonesia dictionary. Others are subject specific, diving into the minutiae of discipline-specific language. Most dictionaries are just one volume long, but some begin to look more like encyclopedias. The Oxford English Dictionary, for example, contains 20 volumes, but is really a dictionary. In addition to the definition of each word, the OED contains all the definitions a word has had over time as well as references to the first few times any word has been documented as used.
Thesaurus provides synonyms for words with related meanings. You might choose to use a thesaurus when you are looking for alternative definitions to words you find yourself using frequently. Thesaurus often include antonyms, or words with the opposite meaning of the one you look up, which can also be helpful when trying to determine alternative ways to say the same message.
A glossary is a list of words typically found in the back of the book and includes the spelling and meaning of the key words found within the book. The words in a glossary are all related to a specific subject. Unlike dictionaries, which are more general collections of words, glossaries only concern themselves with terms that will enhance one’s comprehension of a certain topic. The meaning of ‘prestidigitation’ is not imperative to your understanding of sociology; therefore, a glossary of sociological terms won’t bother to define it. However, you should be able to see it defined in an English dictionary.