In order to publish a website online, you need a Web host. The Web host stores all the pages of your website and makes them available to computers connected to the Internet. The domain name, such as "sony.com," is actually linked to an IP address that points to a specific computer. When somebody enters your domain name into their browser's address field, the IP address is located and Web site is loaded from your Web host.
A Web host can have anywhere from one to several thousand computers that run Web hosting software, such as Apache, OS X Server, or Windows Server. Most websites you see on the Web are accessed from a "shared host," which is a single computer that can host several hundred Web sites. Larger websites often use a "dedicated host," which is a single machine that hosts only one website. Sites with extremely high amounts of traffic, such as apple.com or microsoft.com, use several computers to host one site.
If you want to publish your own website, you'll need to sign up for a "Web hosting service." Finding a good Web host shouldn't be too hard, since their are thousands available. Just make sure the Web host you choose offers good technical support and ensures little or no downtime. You'll usually have to pay a monthly fee that varies depending on how much disk space and bandwidth your site will use. So it's a good idea to estimate how big your site will be and how much traffic you expect before signing up for a Web hosting service.