Store groups allow for a fulfillment center to make decisions for multiple websites at one time instead of having to do it one at a time. These group decisions revolve around determining what is available as far as coupons, shipping methods, payment methods, product groups, and blank products. The most commonly used of this group is setting what “Blank Products” are available to certain affiliate websites. Within the settings of a product (admin), its availability can be set to on or off for certain websites or a group of websites. Website Groups make it much easier to make a product available or not available across multiple websites with a simple click.
For example: lets say you have multiple restaurant and school affiliate clients / websites. The restaurantes might want to sell products that might be inappropriate for a school, like shot glasses, or more revealing apparel. If you put the restaurants websites in one group and schools in another it is very easy to make it so that these products are available where they should be.
To make a website apart of a particular group you need to go into that website’s administrative settings - store groups - and then add it to a certain group.