RSS stands for Really Simple Syndication. It’s a syntax that lets you “publish” news articles with abstracts, in a common format that Web browsers and news-aggregating software can understand.
When you publish content in RSS, people can subscribe to that content with their browsers or news aggregators, and be alerted when there are updates. So publishing an RSS newsfeed lets you stay in touch with your audience.
It’s also possible to create multiple RSS newsfeeds, to appeal to different parts of your audience.
None, but there are several competing formats to choose from within RSS. Choosing one is a technical issue.
RSS is useful when you intend to post a steady stream of news, update, or articles that can keep your audience engaged.
One common use of RSS is to offer the user a drop-down list of article or page titles from her browser’s header bar. Clicking on one of these titles takes the user to the full article on your website. In this way RSS can directly increase your website traffic.