What is a feed?
A feed is a specially constructed web page where newspapers or blogs 'tell' what articles have been newly published.
Usually, a feed includes 20 - 50 entries, which change depending on the frequency of publication. I.e. if you open / load the feed of a large newspaper again after e.g. half an hour, you will then find e.g. 6 new entries in it, while the 6 oldest entries have been pushed out / deleted.
Each feed entry for an article usually contains an ID, the title, a short description, an author list, the URL of an image, the URL of the original article and a timestamp.