RSS (Really Simple Syndication) is a technology that allows the download of information regarding changes in WWW pages in a machine-readable form (XML format). The reader can thus keep tabs on news items and changes without having to regularly visit pages.
If you aren't yet using any RSS reader yet, you can pick from many varied programs. An example for MS Windows is News Interceptor. You can also use the InfoRSS add-on for the Firefox browser, or the integrated RSS reader in the Internet Explorer browser.