What term is used to describe the driest dunes found in a certain climate zone?

The term "Desert" refers to a specific climate zone characterized by extremely low precipitation, making it one of the driest environments on Earth. Deserts can feature various landforms, including sand dunes, which are often associated with these arid areas. The conditions found in deserts lead to sparse vegetation and high evaporation rates, contributing to the overall dryness of the dunes present in such environments.

In contrast, while the term "Arid" describes a climate with limited moisture, it is broader and can apply to various regions that are not necessarily classified as deserts. The other terms, "Tropical" and "Equatorial," pertain to climates that are typically warm and experience significant rainfall, which does not align with the features of dry dunes. Thus, "Desert" is the most accurate term to describe the specific types of dunes found in the driest climate zones.