A database is essentially a searchable index of books and the articles available in particular journals. All of Nash Library's databases are available to you remotely over the Internet.
Some databases will only provide you with citations to journal articles. A citation provides you with all the information you will need to locate a particular article in a journal.
Many journal databases will supply an abstract along with the citation. An abstract is a short description of the content of a journal article (usually only a paragraph or two). This can be helpful in determining whether the article meets your requirements or not.