Syndication technology allows for people to "subscribe" to news from your website in the news aggregator of their choice. Traditional media - newspapers, television and radio stations, for example - aggregate news from various sources to produce a conglomeration of news. A person using a news aggregator on the web performs much the same task when they subscribe to a variety of feeds that interest them.
Think about all of the information that you access on the web on a day-to-day basis; news headlines, search results, job vacancies, and so forth. A large amount of this content can be thought of as a list; although it probably isn't in HTML < li> elements, the information is list-oriented.
To provide you with this information, web sites can offer an RSS feed , or channel, just like any other file or resource on a web server. Computers then fetch the file to get the most recent items on the list. Most often, people will do this with an aggregator, a program that manages a number of lists and presents them in a single interface, such as Headline Viewer or the web-based News Is Free . Other uses include portal-type sites that are aggregating content for redistribution.
One of the strengths and reasons for the popularity of blogs (web logs) today is in part due to RSS news feeds; today's blogging software also auto-generates an RSS feed that "highlights" the latest entry on the blogger's site - allowing like-minded bloggers to "link" to their contemporary's blog site (via this "news feed") - but that is styled to match their own site.
Creating news feeds with the proper coding ensures that they can be used and read correctly by the news aggregators that draw them. Errors in syntax will result in a "broken feed" that cannot be read and is therefore unavailable to those subscribed to the feed(s).
Like other W3C technologies discussed in this document, the development of the actual code is governed by strict standards that must be met to ensure inter-operability with the various user agents in the market today. However, since news feeds are machine readable, they are easy to validate, and on-line validators exist for that very purpose.