What are Feeds?
Feeds are a way for you to keep track of Jive content updates without having to visit the application. (RSS is a popular feed type; "RSS" stands for "Really Simple Syndication.")
By "subscribing" to the content feed, you're asking to have easy access to information about content changes or additions. A feed brings you a list of updates that you can view in a feed reader (also known as an aggregator). Subscribing to feeds is an alternative to receiving email notifications, in which an email is sent each time content is changed or added (although you can also do both). You might prefer email notifications if you want to receive updates in a more "passive" but immediate way. (Set email notifications on individual items, or Managing Email Notifications to get email about particular kinds of activity.)
You can subscribe to feed (see Using RSS Feeds ) for content lists (such as a list of blogs, discussions, documents, or status updates you'd view), spaces, or discussion threads.