A feed is a machine readable (usually XML) content publication that is updated regularly. Many weblogs publish a feed (usually RSS, but also possibly Atom and RDF and so on, as described above). There are tools out there that call themselves "feedreaders". 

What they do is they keep checking specified blogs to see if they have been updated, and when the blogs are updated, they display the new post, and a link to it, with an excerpt (or the whole contents) of the post. Each feed contains items that are published over time. When checking a feed, the feedreader is actually looking for new items. New items are automatically discovered and downloaded for you to read. 

Just so you don't have to visit all the blogs you are interested in. All you have to do with these feedreaders is to add the link to the RSS feed of all the blogs you are interested in. The feedreader will then inform you when any of the blogs have new posts in them. Most blogs have these "Syndication" feeds available for the readers to use.

One of the most exciting features of blogging tools are the comments. This highly interactive feature allows users to comment upon article posts and link to your posts and comment on and recommend them. These are known as trackbacks and pingbacks . We'll also discuss how to moderate and manage comments and how to deal with the annoying trend in "comment spam", when unwanted comments are posted to your blog.