The essence of objects: concepts and terms

Core concepts in object-oriented technology are defined. The concepts are the basis for characterizing and contrasting various object-oriented technologies. The core concepts are: all objects embody an abstraction, objects provide services, clients issue requests, objects are encapsulated, requests identify operations, requests can identify objects, new objects can be created, operations can be generic, objects can be classified in terms of their services, objects can have a common implementation, and objects can share partial implementations. To address communication problems, a glossary of terms appropriate for the diverse set of domains in which object-oriented concepts are being applied is developed. The definitions are grouped into three sections in top-down order: terms related to abstraction, terms related to requesting services, and terms related to performing services.<>