They live in the perl SDBM Database. Editions are collections of stories. Each story must belong to a edition. Each story is formatted based on the requirements of the edition. Two different editions may have different styles.
Pages are templates that editions are pulled into.
A page may have multiple editions. Stories are entered into a database with the edition that it belongs to. The template file, and the destination file. There is however only one story template for all of the story pages. This template will serve all editions.