For all intents and purposes, there is really no difference between the two. Both refer to complete and full batches of beer that you can purchase through the mrbeer.com website. The difference is really just in the logistics.
Each Hopped Malt Extract (HME) and that Mr.Beer® produces has its own refill. Refills are the most basic configurations of each of the flavors of HME that we produce.
Recipes are different in that each recipe is a unique and individual combination of these same ingredients. We take our HMEs,UMEs,Booster and mix and match them different ways, possibly with different additional ingredients, to achieve different styles of beers.
The recipe will always utilize one of our HME's, and combinations of additional ingredients. They may also call for you to provide additional ingredients like honey or spices which you will provide. Recipes can be a jumping-off point for you to start experimenting with combining ingredients differently for particular flavors and effects in your beer. But the bottom line is: whether you are purchasing a refill or a recipe, you are purchasing ingredients to create a delicious batch of beer.