Definition - What does Per Diem mean?
Per diem is Latin terms that means "by the day."
In the context of the law, per diem usually refers to people who get paid a certain amount per day. If per diem amounts are written into a formal contract, then the amount can be legally binding and enforceable. Per diem rates are often given to temporary employees.
Justipedia explains Per Diem
Per diem can also refer to an amount of money that is given by an employer to cover expenses incurred on a daily basis. So, it can refer to this type of payment in addition to payment for work performed on a daily basis.
Many jobs are paid by the hour or by the year in the form of a salary. However, for some jobs, it makes more sense to pay by the day. For example, military roles that last for only a few weeks, or for a few months, are often paid in a per diem fashion.