A bibliographic record is organized into standardized fields which is necessary for any kind of machine readable data. In addition, the use of these standardized fields increases the speed and flexibility of searching the contents of bibliographic records. Searching software can be instructed to search only the fields that will contain the type of information you need.
For example, a title search will search only the title field of each bibliographic record; a subject search will search only the subject heading or descriptor fields of each bibliographic record.
Each field has a name. These are known as field tags.
Fields and field tags vary from one electronic access tool to another. Variations occur in:
