Each published item in one feed is called post. You can think of posts as emails or articles in newspaper. Like emails and articles, they have title, content and publication/post date. In most of the cases, each post acts like a pointer to a webpage since they are used to let you know about new things on the Internet, such as news articles or personal daily logs.
Hence most of the time post gives a summary or introduction to one topic and includes a link to web page from where you can get more information related to that given summary. This is especially the case for news feeds.
Inside Newzie, posts are represented with ( ) icon.