A Streamer identifies segments of its input. It passes the segments individually to transformations such as Parsers, Mappers, or Serializers, which process the segment data.
A Streamer assumes that the source is composed of:
Any number of repeating segments
For each type of segment, the Streamer defines a transformation that processes the segment.
The repeating segments can be either simple or complex. A simple segment is a single unit of data. A complex segment has its own nested header, repeating segments, and footer.
Headers and footers are always simple segments.