What is the main use of "controllers" in Salesforce B2C Commerce?

Controllers in Salesforce B2C Commerce play a crucial role in managing the flow of data and application logic within the platform. They serve as an intermediary between the incoming requests, usually from user interactions on the storefront, and the processes that need to be executed to respond to those requests.

When a user navigates through a site and triggers various actions, such as adding items to their cart, checking out, or searching for products, controllers handle these incoming requests by executing the appropriate logic. This includes processing user inputs, calling service methods, rendering the right templates, and ultimately determining how the application should respond. By managing application logic effectively, controllers help ensure that the user experience is seamless and that the necessary operations are performed efficiently.

In contrast, the other choices reflect functions that are not the primary purpose of controllers. For instance, managing user authentication is typically handled through security frameworks or services rather than controllers directly. Similarly, while defining custom workflows and storing product data are important aspects of the platform, they do not fall under the primary responsibilities of controllers. Custom workflows would more likely reside in service layers or business logic frameworks, while product data is typically stored in the platform's data model rather than being directly managed by the controllers.