What would constitute an unburned area between a finger and the main fire?

An unburned area between a finger of fire and the main fire is referred to as a pocket. This term is commonly used in fire behavior analysis and wildland firefighting contexts. Pockets are significant as they represent areas that have not been affected by the fire, which can potentially serve as a control line or a barrier to fire spread. Firefighters often look for pockets during firefighting operations, as they can help in planning strategies to contain or control the fire.

In contrast, other terms such as a spot fire denote small, isolated fires that occur away from the main body of fire, while an island generally refers to an unburned area surrounded by burned land. A burned area, as the name suggests, would not be unburned and would thus not fit the description provided in the question. Understanding these different terms and their applications is essential for effective communication and strategy development in firefighting scenarios.