What is the primary difference between a Dining In and a Dining Out?

The primary difference between a Dining In and a Dining Out is that Dining In is a formal dinner event specifically designed for military members and their invited guests, whereas a Dining Out is more inclusive and allows for the participation of civilians. The Dining In event emphasizes military customs and traditions, making it a formal occasion primarily for military personnel. This context of exclusivity and adherence to tradition sets it apart from the more public-facing Dining Out, which encourages a broader social engagement by including civilians and usually has a less rigid format. The correct answer captures this essential aspect of Dining In, highlighting its formal requirement for military-only attendance.