Segments - The Basic Unit Of Data

What is a Segment
What is a Segment
Segments are the basic units of data that an application can access in DL/I. Segments consist of one or more fields, which are the basic pieces of data that an application can use. For example, the EMPLOYEE segment might consist of the employee name, id, and address fields.
Segments can be either fixed length or variable length. Within a segment, individual fields can occur either once or multiple times.
What is a Segment Occurrence
A specific instance of a segment that is stored in the database is known as an
. For example, the data for employee Bob Jones would be an occurrence of the EMPLOYEE segment. There can be any number of occurrences for a given segment.