Really Simple Syndication
(AKA Rich Site Summary, AKA RDF Site Summary)
A lightweight, XML-based format for feeds of information. Generally used for information that is updated on a regular basis, such as news headlines, although it is very flexible and can be used for many types of information.
Because it is lightweight and generally more efficient than a full web page (or even a mobile page), it is ideal for mobile devices where bandwidth and screen size are limited.
RSS-reader software is available for most smartphones.