What best describes the function of the "collection" template?

The function of the "collection" template in Shopify is to provide an overview of product groupings. This template is designed to display a curated set of products that belong to the same category or collection, making it easy for customers to browse through related items. When you create a collection in Shopify, you can group products based on various criteria, such as similar characteristics, themes, or promotional types.

By using the collection template, merchants are able to effectively organize their products on the storefront, facilitating a seamless browsing experience for customers. This is especially important in e-commerce, where customers appreciate being able to quickly find relevant products without having to search through an entire catalog.

The other options mentioned involve different aspects of the Shopify platform that do not pertain specifically to the collection template. Customizing checkout options relates to the checkout process rather than product categorization. The stipulation regarding solely digital products applies to another aspect of product management. Showcasing best-selling items is typically done through a different mechanism, such as a sales or featured products section, rather than a dedicated collection.