When creating a feature class, you always attach it either to a topic or to another feature class, in which case, it is a sub-feature class, or a child class.
To create a feature class, right-click the parent topic, or feature class and click Create Feature Class. The Create Feature Class dialog box is displayed.
After finishing the default settings of a feature class, you can add any required customer attributes. See also Adding Attributes.
Also, you can register a database view as feature class. See Creating a Feature Class From a View.