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.
Second-level (or lower-level, depending on the established parent hierarchy) domain names are often created based on the name of a company (e.g., bbc.co.uk), product or service (e.g. hotmail.com). Below these levels, the next domain name component has been used to designate a particular host server. Therefore, ftp.example.com might be an FTP server, www.example.com would be a World Wide Web server, and mail.example.com could be an email server, each intended to perform only the implied function. Modern technology allows multiple physical servers with either different (cf. load balancing) or even identical addresses (cf. anycast) to serve a single hostname or domain name, or multiple domain names to be served by a single computer. The latter is very popular in Web hosting service centers, where service providers host the websites of many organizations on just a few servers.
If you get a domain name that describes your company's business or name, people can remember the name easily and can return to your site without having to consult their documents. In fact, if you get a good name that describes your product or service, you might even get people who were trying their luck by typing "www.yourproductname.com" in their browser.
Domain names are organized in subordinate levels (subdomains) of the DNS root domain, which is nameless. The first-level set of domain names are the top-level domains (TLDs), including the generic top-level domains (gTLDs), such as the prominent domains com, info, net, edu, and org, and the country code top-level domains (ccTLDs). Below these top-level domains in the DNS hierarchy are the second-level and third-level domain names that are typically open for reservation by end-users who wish to connect local area networks to the Internet, create other publicly accessible Internet resources or run web sites.