Magento 2 virtual products are products that have not to weight and that you can not ship. Such products are membership, services, warranties, subscriptions, digital downloads of books, music, videos, or other products.
When creating a downloadable product in Magento 2, you need to configure the Download Options to determine when the download becomes available in the frontend, and specify if non-registered users can purchase and download the product.
Magento 2 downloadable product is one of the product types that Magento 2 support by default. Magento 2 downloadable products are products that you can deliver as a file, such as an eBook, music, video, software, apps.
A bundle product is one of the product types that comes with Magento 2 by default. It's is a group of items that consist of simple and virtual product types. Each item in the bundle is a standalone product.