Push

A general term that is used to describe technologies that allow a central system (e.g. a mobile phone network) to send (push) information quickly to an end-user without any action needed on the part of the user or mobile device.

For example, with push email, emails are sent directly to the mobile device as soon as the email server receives them, without the user having to manually check for new email, or the mobile device having to periodically check the server. Many 3G phones have the push-email feature. SMS (text messaging) is inherently a "push" technology.