(1) To provide a source of information that users select from and then receive on a regular basis or when certain events occur. The service can be public or private, free or paid, and information can be provided via email and the Web or by means of proprietary applications. For example, a stock trading application lets you select particular stocks, and those quotes are sent to you on either on a regular schedule or when there is a change in price. See
push technology.
(2) (Publish and Subscribe) A Mac capability starting with System 7 that provides hot links between files. All or part of a file can be published into an "edition file," which is imported into a subscriber file. When any of the published files are updated, the subscriber file is also updated.