A theory of explanation might treat explanations in either a realist or an epistemic (that is, anti-realist) sense. A realist interpretation of explanation holds that the entities or processes an explanation posits actually exist--the explanation is a literal description of external reality.
Officers in pay grades O-1, O-2, and O-3 with more than four years of prior cumulative service in an enlisted or warrant officer grade are paid increased wages using the special pay grades of O-1E, O-2E, and O-3E, respectively.
A wage is better because you get paid for how many hours you work, while, with a salary, you get a set amount of payment. An example of a job that gets a salary is a teacher. It doesn't matter how much homework they grade over weekends and vacations, they get the same amount of money. What a Salary looks like: $45,000 per year.