What is the difference between a product set and a bundle in B2C Commerce?

Both product sets and bundles are types that group multiple products together, but they behave differently for the shopper and in the cart:

1. Product set — a curated collection of products displayed together on a single page (e.g., "complete the look" or "shop the outfit"). Each component is purchased independently — the shopper can add all, some, or none to the cart. Each component becomes a separate line item in the basket at its own price.
2. Bundle — a group of products sold as a single combined unit at an aggregate or discounted price. All components are added to the basket together as a single line item. The shopper cannot partially purchase a bundle — it is all or nothing.

In the product catalog, set and bundle products have their own product type (ProductSet and Bundle), and the SFRA Product Detail Page controller handles each type differently — rendering either individual "add to cart" buttons per component or a single "add bundle to cart" button.