Related products are additional products that can appear on a product page, allowing you to cross-sell and upsell.
Types of related products
There are two types of related products they are:
Parent related products
This is the product you want to show the related products from.
Child related products
This is the linked product, it will show under the products that are associated with the parent product, for example in the picture above the Parent Product is the Stainless Steel Water Bottle.