Binary versus normalized geometry
The SOAP API contains a number of concrete geometry classes (e.g. PointN, PointB) that derive from abstract types (e.g. Point). The concrete classes are divided into two types: Normalized and Binary. Normalized type names combine the geometry type name with the capital "N" (e.g. PointN). When geometry is normalized, its properties are serialized to XML. The XML schema matches that defined in the SOAP API, thus normalized geometry types should be used when working with the SOAP API.
Binary type names combine the geometry type name with the capital "B" (e.g. PointB). When geometry is serialized as binary, it is represented as a byte array that contains a base64 encoded xml string. Binary types are only designed to be used internally by Esri desktop products. They are not designed for general public use via the SOAP API.