Desktop Notifications is a feature defined and used by Google (with Google Chrome and GMail products) for displaying notifications integrated in the user's own desktop when an event occurs.
SaltOS, also adds support to redirect notifications that appear within the application to the user's desktop. For example: when receiving a new mail, a new post or just trigger a calendar alarm, SaltOS shown in the user's desktop a message indicating the event.
Additionally, SaltOS includes other mechanisms to alert users as favicon animation and voice notifications, allowing users to hear the messages and to hear the subjects of the mails, posts and events.
For Firefox, there are extensions that add support to the browser to use the integrated desktop notifications: https://addons.mozilla.org/es-ES/firefox/addon/html-notifications/