Digital reference
The word "reference" in a library context refers to two related but different things: (1) reference works, such as dictionaries, encyclopedias, etc., and (2) reference work, which is the task of providing assistance to library users in finding information, answering questions, and otherwise fulfilling users’ information needs. Reference work often but not always involves using reference works.
The Reference and User Services Association defines a reference transaction as "an information contact that involves the knowledge, use, recommendations, interpretation, or instruction in the use of one or more information sources by a member of the library staff." In other words, the reference transaction is the interaction between the user and the librarian, in which the librarian attempts to help the user to fulfill an information need.
Digital reference is a service by which reference work is conducted online, and the reference transaction is a computer-mediated communication.