Bush plane
A bush airplane is a general aviation aircraft used to provide unscheduled passenger and freight services to remote, undeveloped areas of a country, such as the Alaskan tundra, the Canadian north (or bush), the African bush, or the Australian Outback. They are used where ground transportation infrastructure is inadequate or doesn't exist.
Common traits
Since a bush plane is defined by how it's used, a wide variety of different aircraft with different configurations have been used over the years as such, however experience has shown certain traits to be desirable, and so appear frequently, especially on aircraft specifically designed as bush planes. None of these traits are mandatory - merely that they are commonly seen features of bush planes.
The undercarriage is designed to be fitted with floats, skis or wheel/skis to permit operation from water or snow (primarily for Alaskan, Canadian and Russian use).
High wings ease loading and unloading, particularly from docks, as well as improve downward visibility during flight and increase clearance to reduce the potential for damage during landing or take-off. A high wing is less likely to be damaged during loading or unloading than a low wing.