A feed is a common technique used for sharing content on the web for reuse. You will use information provided in this feed in an RSS reader.
To subscribe to this feed in your RSS reader you will need the web address (URL) of the feed: http://asthma.osu.edu/rss.cfm. Just copy and paste this link where your RSS Reader software asks for a URL.
If you are not familiar with what RSS is and would like to learn more, visit Wikipedia for an explanation or watch the following video from Common Craft.