RSS Feed Technology
Term RSS marks four HTTP data transfer protocol over Internet (feed):
- Rich Site Summary (RSS 0.91 extension .xml)
- RDF Site Summary (RSS 1.0 i RSS 0.90 extension .xml)
- Really Simple Syndication (RSS 2.0 extension .xml)
- Atom Syndication Format (Atom extension .atom ; .xml)
RSS (shortcut for Rich Site Summary, RDF Site Summary, Really Simple Syndication - really simple news; as well as a sign for Atom feed format and protocol) is a "family" of HTTP protocols/formats that enable data distribution over the Internet.
RSS feeds do not use HTML Internet language HTML (Hyper Text Markup Language) so regular Internet browsers cannot be used to see content (e.g. Internet Explorer, Firefox, Opera, Safari).
RSS avails for a quick Internet content checksum, because informations are "cleaned" from unnecessary data that contain HTML language that Internet is based on.
Big advantage of RSS feed is based upon its speed and simplicity in web pages viewing.
It is not necessary to go to web pages to see the newest changes (news and similar informations that are being changed every few minutes). By RSS readers, you can "fly over" the newest changes on several websites in just few seconds. It is usually done automatically (in scheduled time) and RSS informes you about the new changes.
RSS feeds are used by websites that change its content regularly, web blogs and websites that want to make viewing easier to its visitors (RSS feeds don't include commercials).
For website owners RSS feeds are a way of promotion, because it attracts new visitors by short view of websites' contents. If visitors want to read whole story they'll come to the website over the links given.
Note for all concerned about SEO and duplicated content:
Google do not sanction neither ones with original content, nor ones that duplicate it if there is a link to the website with the original content! More information on SEO can be found here.
That is why you should not hesitate to put RSS on other websites, or to be frighten to public copies of content from other websites. The only rule that should be respected is to public only RSS feeds with the same or similar topics.
It is a gain for all, especially for your website visitors!
Website/blog that provides RSS feed for visitors can be recognized by characteristic (in most times orange icon) 
in the bottom right corner of your browser (Internet Explorer, Firefox, Opera...).
To see RSS feed you need to have "reader" for RSS feeds (known as RSS readers, feed readers or aggregators).
There are two types of readers:
- Desktop - it's a "reader" you install on your computer. RSS reader is not integrated with Windows operating system. That is why it needs to be downloaded from the Internet. These programs are free (for now).
- Web (internet) reader. It is "online" RSS "reader" and it can be used over browsers ( Internet Explorer, Firefox, Opera or Safari ). It is placed on websites. This service is also free (for now), and most RSS online services don't ask you to register (it is mostly for spam protection).
