(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 e-mail 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 Macintosh 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.