If you ever change your web host (the actual physical location of your website files), your domain name goes with you. Your regular visitors or customers who knew your site name as (say) www.thesitewizard.com would not have to be informed about a change of web address (also known as "URL"), since as far as they are concerned, the site is still at the same place. They would simply type your domain name and they'd be transparently brought to your new location.
Domain names serve to identify Internet resources, such as computers, networks, and services, with a text-based label that is easier to memorize than the numerical addresses used in the Internet protocols. A domain name may represent entire collections of such resources or individual instances. Individual Internet host computers use domain names as host identifiers, also called host names. The term host name is also used for the leaf labels in the domain name system, usually without further subordinate domain name space. Host names appear as a component in Uniform Resource Locators (URLs) for Internet resources such as web sites (e.g., en.wikipedia.org).
Domain Privacy prevents these spammers from collecting your personal info. DreamHost’s complementary (yes it’s free for the life of your domain) Domain Privacy service works by masksing your personal information in the WHOIS database with DreamHost’s corporate information, so you’re protected from unscrupulous marketers, spammers, robo-callers, junk mailers, and stalkers.
The suffix identifies the name as belonging to a specific top-level domain (TLD). As of late 2016, when this article was written, there are numerous TLDs available for general purchase, including .com, .edu, .game, .green, .hiphop, .net, and .org. The most popular of these by far is .com, which is supposed to indicate commercial sites, but in reality has come to include almost everything.
Anyone can buy a domain name. To do so, you visit a domain name registrar, such as GoDaddy or Namecheap, key in the domain you want to buy, and pay a fee. You can't buy just any domain, of course—only one that isn't already registered by another person or business and that bears a valid domain suffix. In general, you'll want to buy something that is catchy and short so that it's both easy for people to remember, and easy for them to type in—like "PCMag," for example. That good search engine optimization (SEO) and it's also common sense. You might also want to do some research on key terms for your business. If you can get a good one into your site's name, that's all the better, from an SEO perspective.