A prep recipe is a standardized set of written instructions that describe the preparation and pre-preparation needed to finalize a menu item.
The ingredients of prep recipes may consist of stock items (such as tomato, bell pepper, salt, etc.) and other prep recipes.
Such prep recipes, which are under another prep recipe and usually are not used alone when produced, are called sub-recipes or secondary recipes. All sub-recipes are basically a prep recipe.
However, a sub-recipe may contain other sub-recipes besides stock items.
Service recipes are the recipes for the menu items that are ready to be served to the guests and are highly correlated with the prep recipes. These recipes contain information on how to assemble and finalize a menu item.
Service recipes mostly consist of prep recipes. However, they may contain stock items as well.
In addition to this, service recipes explain cooking and plating steps, the necessary equipment for presentation, and some other essential information about the menu item.
Service recipes are a written document that details how the cooks will finalize (presentation) the menu item. They are also a training guide for both kitchen and service staff.