Marketing Operations and xConnect
Marketing definitions give contextual meaning to interaction data that is submitted to xConnect. For example:
Every interaction must be instantiated with the ID of a channel definition.
Every event, goal, or outcome that is added to an interaction must be instantiated with the ID of a event, goal, or outcome definition.
When interaction data is aggregated into the reporting database, each aggregation processor can use the Marketing Operations API to look up additional information about the referenced definition for reporting purposes.
Marketing Operations and Reference Data
All Marketing Operations definitions and taxonomies are deployed to the Reference Data service. Callers within the xDB ultimately access definition and taxonomy data via the Reference Data Service rather than the master or web databases. For example, dedicated Processing servers and the Marketing Automation Engine both use the Marketing Operations API with a Reference Data Service repository.
Prior to Sitecore 9, definitions were deployed to the xDB Reporting database. In Sitecore 9 and later, definitions are only deployed to the Reference Data service.