Domain names and IP addresses is one to one, of course, can also be multiple domain names corresponding to an IP, but the computer is a domain name can not be identified, so the domain name parsing, converting it into the corresponding IP is a must, and this resolution services provided DNS server is, in fact, every time you open a web page, you may have experienced hundreds of domain name resolution, it is clear that if the DNS server is too busy, it may be more analytical process slow, slow Internet speed is a direct consequence, so choose a good resolution server is necessary.
Getting a domain name involves registering the name you want with an organization called ICANN through a domain name registrar. For example, if you choose a name like "example.com", you will have to go to a registrar, pay a registration fee that costs around US$10 to US$40 for that name. That will give you the right to the name for a year, and you will have to renew it annually for (usually) the same amount per annum. Some web hosts will register it and pay for the name for free while others will do it for you but you'll have to foot the registrar fees. To register the name directly with a domain name registrar rather than through my web host. Registering with a domain name registrar allows to make sure registered as the owner, the administrative and technical contacts. Being the owner is vital — if someone else places himself as the owner, he can always decide to