The gxp components and data utility classes extend map related functionality to equivalent classes in Ext. The API reference here documents the properties, methods, and events that are extensions or modifications to the Ext parent classes. Documentation for each class contains links to the Ext parent class, and for a full picture of the API, it is essential to have a copy of the Ext API Documentation at hand.
gxp classes are typically configured with OpenLayers or GeoExt objects. For detail on methods and properties provided by these objects, see the OpenLayers API Documentation and GeoExt API Documentation.