Most businesses will need a hosting service to launch their website. You are not tied to the place where you have registered your domain name. A hosting service is paying for server space to load your website files. After your files are loaded then you would tell the domain name where to look by updating the DNS information where your domain name is registered.
And I've probably lost you from boredom already! Basically, hosting is one of the most important things in making sure your site is up and running. I've used quite a few shared hosting providers over the years and they range in price and quality a great deal. In shopping shared hosting services, you should consider the user interface, support, performance and pricing.