Private applications can interact with the Shopify API on behalf of how many stores?

Private applications are designed to interact with the Shopify API specifically for a single Shopify store. This is by design, as private applications are tailored to meet the needs and requirements of a unique store instance, allowing for customized functionalities and integrations that fundamentally relate to that store's operations and data.

This exclusivity ensures that security and data integrity are maintained since private apps have access to sensitive store information and allow for specific permissions that pertain only to that one store. In contrast, other application types, like public apps, can be designed to integrate with multiple stores but require different permission handling and operating frameworks. Therefore, the accurate understanding of private applications is that they serve a singular store, emphasizing the tailored and secure nature of their function within the Shopify ecosystem.