A domain name is, quite simply, the name of your website. The domain can be found in the URL and is used in order to locate the website of a specific person or organization. Each domain name or URL directs users to a specific IP address. Domains are easier to remember than a long and complicated IP address, which takes the form of a series of numbers. A domain can be divided up into three different elements: a subdomain, a domain name, and a top level domain (TLD). Take about.1and1.com as an example: the 'about' element is the subdomain, the '1and1' element is the domain name itself and the '.com' part of the URL is the top level domain. It is also possible to have multiple subdomain levels, info.about.1and1.com for example, which you can use to segment your website into separate categories. The length limit of a complete domain name is 255 characters. With 1&1, you can choose a domain name that best suits you or your business, or you can transfer an already existing domain over to 1&1. Next, customers can select a TLD from a wide variety of domain extensions on offer. When choosing a domain name, it is important to select something that properly reflects the ethos of your business in a concise and catchy way. A good domain should be memorable, brandable, and should have a suitable extension.
The practice of using a simple memorable abstraction of a host's numerical address on a computer network dates back to the ARPANET era, before the advent of today's commercial Internet. In the early network, each computer on the network retrieved the hosts file (host.txt) from a computer at SRI (now SRI International), which mapped computer host names to numerical addresses. The rapid growth of the network made it impossible to maintain a centrally organized hostname registry and in 1983 the Domain Name System was introduced on the ARPANET and published by the Internet Engineering Task Force as RFC 882 and RFC 883.
My personal preference is to register the name directly with a domain name registrar rather than through my web host. I've heard stories, in the past, of less-than-reputable web hosts that registered the domain under their own name, making them the owner of the domain rather than you (although I don't know if such web hosts still exist today). Registering direct with a domain name registrar allows me to make sure that I am registered as the owner, the administrative and technical contacts. Being the owner is vital — if someone else places himself as the owner (such as your web host), he can always decide to charge you some exorbitant fee for the use of the name later, and there is little you can do. The various other contacts are less vital, but may still play important roles, depending on your registrar. For example, for some registrars, the administrative contact's approval is required before a domain name is transferred out of a web host (or at least, it used to be). If he/she cannot be contacted, the technical contact is used.
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 can be used in a number of ways. Direct visitors to your website’s home page or use complementary domains to send them to specific areas of your website ( e.g. yourcompany.jobs for a careers page). Or, forward a custom domain to an existing social media account, like your Twitter profile or Periscope channel. With a domain name you can even set up custom email addresses like firstname.lastname@example.org, which can be used to conduct business or communicate with your followers. More.