A class is a designation for a group of features in a broadly defined descriptive category. All features are assigned to one and only one class.

The class terms originally were chosen for computer search and retrieval purposes. These categories do not individually identify all kinds of cultural and natural features. They largely agree with dictionary definitions, but represent more generalized categories.

See Feature Class definitions. Commonly used generics are listed in parentheses at the end of each entry to assist in understanding the range of cultural and natural entities represented by the term.