Summary: Use ecommerce category pages for complex products or subcategory navigation. For other situations, consider a hybrid category page approach.
Sites with large inventories or complex products often provide category pages as well as product-listing pages. Category pages act like homepages for a particular product category. They don’t provide a complete list of products but may showcase a few products and provide links to product subcategories. They are, essentially, an intermediary step that users pass through on their way to a product-listing page.
Category pages often provide some combination of:
Dedicated category pages are not necessary for all products. Sometimes they can actively annoy customers because they require an extra step to see product options.