Persistent objects - objects that can be saved to and restored from a data store. Persistent objects represent the records in a table and encapsulate all the required relationships. The field values are represented as properties. Therefore a data table is merely represented by a collection of persistent objects. With eXpress Persistent Objects you will never have to deal with table mapping - all you need to do is to define persistent object classes, and XPO will automatically generate a database for them.
XPO classes can't be used as design-time Data Sources in VS 2005 since the base XPBaseObject class implements the System.ComponentModel.ICustomTypeDescriptor interface to provide dynamic type information. You should use, for example, the XPCollection or XPView as a data source for editors and grids.