An index is a guide to the articles published in many different periodicals, journals or magazines. This allows a user to search by terms from the thesaurus and view citations for all of the articles on the same topic, whether or not the subject terms actually appear as words in the article's title. You will need this type of article-level information to order articles. Most document delivery services require the journal name, article title, author and details such as issue number and date of publication. An abstract is a concise summary of the content of a specific article.
Abstracts vary in length and in the amount of information they contain.
They may be created by the same author as the article, by the journal editor, or by the index producer. Reading an abstract can help you decide if you need to read or order the entire article. Reading abstracts for several articles in the same journal is useful for users deciding whether to order a subscription, to authors deciding where to submit an article for publication, and so on.