When you type google.com into your browser, the domain is split into parts by the “dot”, from right to left. The first part is “com”, so your computer checks the root zone file to see which registry manages the .com TLD. It then checks with this registry to see where the next part, “google”, points to. The registry returns the IP address 126.96.36.199, and your computer can then ask Google to send their homepage over.
If you do not have a web host, you can always allow the registrar to park your domain name at a temporary website specially set up for you. This way you can quickly secure your domain name before it's too late and still take your time to set up the other aspects of your site. As far as I can tell, most registrars (or probably all) automatically park your domain by default whether you ask them to or not, so if this is your situation, you probably don't have to do anything special to get it done. Some of those registrars also provide you with a free email address at your own domain name while it is parked at their site, like email@example.com (where "example.com" is your domain).
Domain names were created to make IP addresses easy to remember. Every computer has an IP address assigned to it – much like a street address. But instead of having to memorize each IP address number, we assign domain names to these numbers so we can easily remember them. The domain name system, or DNS, takes domain names and translates them into their IP addresses so that computers can communicate with one another. When you enter a domain name into your web browser, the browser simply uses that domain to locate its corresponding IP address and then shows you the website associated with it. If you own a business, GoDaddy can help you find a domain name that best suits the business so you can easily promote your website.