development mode: Uses derived properties so that you can preview a product catalog on a web site while you’re making changes without having to run the CatalogMaintenanceService (see Using the Catalog Maintenance System in this guide). Development mode makes updates incrementally so you can preview your changes throughout the development process.

Development mode overrides the definitions of certain properties in the catalog repository that are normally computed by the batch service, and these properties are derived on-the-fly. Development mode is more resource-intensive than production mode because these properties have to be computed at the time they are referenced, rather than being pre-computed by the batch service.

production mode: Uses computed properties. This mode uses properties pre-computed by the CatalogMaintenanceService, so performance is superior to development mode.