What does the difference aud mean for a single room?

A single room margin is a term in the travel industry that refers to the additional cost a person pays to stay in a room. Usually, travel agencies calculate travel costs based on double rooms. If tourists choose to stay alone, they need to pay the difference for a single room. AUD is the currency symbol of the Australian dollar, so the single room difference AUD refers to the single room difference cost calculated in Australian dollars.