This is the main principal you should remember which will transform the way you see how internet works for blogs visibility. This principal is the reason why XML important for blog and is regarded as standard communication languages that convey information.
XML is one of those three letter acronyms that stands for Extensible Markup Language. XML is basically allows computer to share information and documents on a very high level that allows software programs to talk and share information with each other, which is highly powerful than HTML. XML facilitates websites, search engines and software programs to share information in ways never before possible. XML is not a language that you probably would ever want to learn or read but it is very very important for the survival of your blog.
XML is capable of describing many different kinds of data. Its primary purpose is to facilitate the sharing of data across different systems, particularly systems connected via the Internet. Languages based on XML (RSS, Atom, OPML, RDF) are defined in a formal way, allowing programs to modify and validate documents in these languages without prior knowledge of their form XML is very readable from a computer-to-computer level, which means that the search engine spiders like content in this format and they will quickly index this information.
By presenting information to the search engines in XML, you can have the search engine bots automatically coming back to your site at your command, instead of having to wait up to a month to have them visit your site. The bots will come and index immediately after they have been told that you have an updated XML file. This process is called pinging. XML allows for your information to be delivered directly to the consumer’s desktop once they choose to subscribe to your XML file (in a feed reader). HTML displays data. XML describes data. Remember this statement, it is a key point. The main difference between HTML and XML is that HTML is about displaying information, while XML is about describing information.