Domain

The domain name (domain name) is given a unique name to identify the name of the server computer as a web server or mail server on a computer network or the Internet. The domain name serves to simplify the user on the internet at the time of access to the server, but is also used to remember the name of the visited servers without having to know complicated series of numbers known as IP addresses. This domain name is also known as a unity of a website. The domain name is sometimes also referred to as a URL, or website address.

Domain Naming System; SNR (English: (Domain Name System; DNS) is a system that stores information about hostnames and domain names in the form of scattered data base (distributed databases) in a computer network, such as the Internet. DNS provides the IP address for each host name, and lists the mail transmission server (mail exchange server) that receives e-mail (email) for each domain.The system outlined above provides a simplified scenario. The DNS includes several other functions:• The host name and IP address does not mean a one-to-one basis. Many hostnames may correspond to a single IP address: combined with virtual (virtual hosting), this allows one computer to serve many web sites. In addition, a host name can represent multiple IP addresses: this will help fault tolerance (fault tolerance and load distribution (load distribution), and also allows a site to move from one physical location to physical location seamlessly.• There are quite many uses DNS besides translating names to IP addresses. Example:, mail transfer agents Mail transfer agents (MTA) uses DNS to find the purpose of sending E-mail to specified address. Domains that inform the exchange mapping is provided through the record MX (MX record) is an additional layer to enhance fault tolerance and load distribution apart from the function name to IP address mapping.• Delivery of the Framework Regulation (Sender Policy Framework) controversially takes advantage of a DNS record type, the TXT record.• Provide flexibility for computer failure, multiple DNS servers provide protection for each domain. Precisely, thirteen root servers (root servers) used by the whole world. DNS programs or operating systems have the IP addresses of this server. United States has, at least nominally, all but three of the root servers. However, because many root servers actually implement anycast, which allows several different computers can share the same IP address to transmit a single service over a wide geographical area, many servers that are physically (rather than nominal) located outside the United States.DNS uses TCP and UDP on port 53 to serve requests. Almost all DNS queries consist of a single UDP request from the client followed by a single UDP reply from the server. TCP typically comes into play only when the response data size exceeds 512 bytes, or for such zones DNS zone transfer