Can you tell me exactly how I can use XML today to improve my Web sites?
To put it bluntly, no. XML is actually an evolving set of tag-like commands that industries are developing and standardizing upon still and will be for a long time. For now, it's important that you understand the overview of XML and that it enables HTML-like tags to describe your data, not just format your data. Later, when another program or Web site scans your documents and Web sites that contain XML, those sites will be better able to automatically understand the type of content your site and documents hold and don't have to base their assumptions on perfect keyword matches, which is error-prone at best.
Should I host my own site?
If you have a high-speed Internet connection, a very fast second computer that you don't need to use exclusively, and an Internet connection that is set up with a fixed IP address ( Internet Protocol address ) so when you link a .com domain to your location, that location won't change, you can host your own Web site, as well as charge others to host theirs. But really your work has just begun. You must be completely on top of backing up the server constantly or you could very easily lose your (and your clients ') Web data due to an electrical problem (rare) or a hacker attack (less rare). You must constantly update your security to have the latest security patches so the latest hacker breaches don't successfully enter your server's files from somewhere else in the world. You'll need to understand networking protocols deeper than you think you do as well.
If you're willing to devote the time and resources just described, sure you can host your own site. Many people do just that. Nevertheless, the majority of Web-site owners like the freedom of paying a hosting service a monthly fee and let them handle the hosting headaches . You can then concentrate on what is truly important, and that is the content that you place into your Web site's pages.