Release 10.1A: OpenEdge Getting Started:
Object-oriented Programming

Comparing handles and object references

A procedure object handle always references a running procedure instance, and is stored in a variable or field of type HANDLE. An object reference always points to an instance of a class and is stored in a variable that is defined as that class, super class, or interface type, or in a temp-table field of type Progress.Lang.Object. These two reference types are not interchangeable.