The description of a FOCUS file is a series of comma-separated attributes which are stored in a file which is identified as a Master File.

A Master File can refer to an Access File. The Access File provides comprehensive metadata management for FOCUS data sources. It shields end users from the complex file storage and configuration details used for access to partitioned and distributed data sources.

The Access File is a series of blank-separated attributes that describe how to locate, concatenate, join, and select the appropriate physical data files for retrieval requests against one or more FOCUS data sources.

Access Files are optional, except for retrieval requests using intelligent partitioning. One Access File can contain information for one or more Master Files.

A Business View (BV) of a Master File groups related items together to reflect an application's business logic rather than the physical position of items in the data source.