What is RSS?
RSS stands for "Rich Site Summary". RSS is a way to easily disseminate news items, update notices, and content to a large number of people without the need for them to continually visit the website. RSS is used by software to aggregate and present the content to you in a organised structure.
Why use it?
RSS allows users to avoid manually inspecting all of the websites they are interested in, and instead subscribe to websites such that all new content is automatically checked for and advertised by their browsers as soon as it is available.
How do I subscribe?
RSS feeds can be read using software called an "RSS reader", "feed reader", or "aggregator", which can be web-based, desktop-based, or mobile-device-based. The user subscribes to a feed by entering into the reader the feed's URI or by clicking a feed icon in a web browser that initiates the subscription process. The RSS reader checks the user's subscribed feeds regularly for new work, downloads any updates that it finds, and provides a user interface to monitor and read the feeds.
A list of RSS readers and aggregators is available at http://en.wikipedia.org/wiki/Comparison_of_feed_aggregators.