The term war fighter is distinct from service member. War fighter means mission critical and typically in a theater, while a service member might be someone sitting behind a desk in a less critical role. Similar to having mission critical production systems and supporting production systems.

When you perform your business impact analysis, these will bubble up in different ways, requiring some differences to the playbooks.

There isn’t really a distinction day to day on this in practice. It covers everybody - just easier to say than all the official titles and typically for morale helps to carry the name all the way to the back office to connect to what’s happening at the pointy end.