At first sight can seem that the domain and a host are almost the same. However by detailed consideration it becomes clear that it absolutely not so. The domain is a name of your website which you think out, and then buy, and the host is a physical placement of your website on a certain server. This service is provided for a fee.
What is a host
Host (from English host – "the owner receiving guests") – any device providing services in client-server technology for any interfaces is also unique defined on this server. This that place where different information, for example, your website because the concept "host" is most often used in connection with placement of a web resource on the Internet is stored. In more special case a host is called the local computer connected to the Internet. For designation of a host its network name is used – if a host is the home computer, and the domain or the IP address – if it is about a host on the Internet.
Many websites determine uniqueness of visitors by hosts as to each unique visitor of a resource there corresponds one host (that is the local computer with Internet connection). The concept of a host is adjoined by such concept as a hosting. The hosting is understood as the server on which the files available always to certain clients are stored. The server on which, your resource will be placed can be in other city and even in other country. Services of a hosting are provided by the companies on a paid basis. Even the computer for house use can act as a hosting provided that on its hard drive the special program, for example, of Apache will be installed. Let's say on the local server several folders are planned to arrange, access to each of which will be had only by the certain user, that is each user will be able to be included only in the folder. Besides, at this hosting it will be obligatory a hoster – the person having access to all folders and configuring the server.
Why the domain is necessary
The domain (from English domain - "sphere", "territory") is area of space of the hierarchical names which are identified the domain. In other words, the domain is understood as the website address, his name. The name to the website, or the address, is necessary to show to visitors the road to a resource.
Each computer entering into the Internet has the unique domain address (domain address), or in a different way a domain name (domain name), or just a name of a node (host name). The address, or the domain, exists in the form of a word, sometimes digits, separated by points. In a name depends on quantity of points what domain of level before us. Most often domains of the first (or top), the second and third levels meet.