These are the main database files for Replenish and ReStore (ex: Product table, Supplier table, Suggested Orders table, etc…).
The Night Job (objects contained in K3S_5OBJ and invoked at a set point after the completion of your EOD process) does the majority of the calculations and updating of the system. Every night K3S will pull directly from your database (if the install is on premise) or receive a copy of a few files via CSV over SFTP, and import them into the database for processing.
All interfaces are expected to work through APIs to delete, update, or create records in the database. Querying may be done directly. This technique is referred to as CQRS.