RSS, how it works?

The RSS system to publish articles and news over the web is very simple:

1. There are firstly some web pages, one want to be displayed by other websites.
   This set of pages is the RSS feed.
2. An XML file that defines the RSS feed. This file holds URL, title and summary of each page to display.
3. A person which want to read the feed on its computer. He (she) uses a RSS reader and just adds the feed with the proper command of the program.
4. Or another website that wants to display the feed. It has to load the RSS file from the provider, to extract URL of pages, and display titles and summaries. This may be performed by a php script.
5. When someone visits the website of the receiver, the script is launched, it recalls the RSS file from the provider's website and displays a list of news from extracted data.
6. By a click on a line of the list, visitors display a page from the provider.