RSS is the abbreviation of "Really Simple Syndication". Basically RSS is a sort of publishing of the web content. Technically RSS is a document which is compatible with XML(Extensible Markup Language) 1.0 specification which are defined by World Wide Web Consortium (W3C).

We are using the RSS technology to publish actual 10 real estate listings in http://em-store.com.

You do not use only such software which are programmed especially for this purpose, but also some web browsers(Firefox, Opera, Safari, etc.) can read the RSS. You can use page in Google to reach RSS softwares.