H - The Web Architecture and Components which enable Internet and Web Functionality - Part 1 by liwenting


									                    Website Design / Web Development / Website Production


   The purpose of a hosting service and the typical functions

   Examples of website hosting companies and identify the
    services each offers.

    Hosting Review – Top Ten UK Hosting Companies

    Top10 Best – WebsiteHosting.co.uk - The Top 10 Web Hosting Companies of 2011

   The domain system - a domain diagram and explanation of the structure of a domain

   The role of a domain name registrar and find out the registrar of a chosen domain

    ICANN (Internet Corporation for Assigned Names and Numbers) is a non-profit
    corporation that is responsible for managing the assignment of domain names. ICANN
    accredits a number of domain name registrars, these registrars then delegate or lease the
    domain name to an end user or registrant. Once a registrant has leased or bought a domain
    name from a registrar they are free to use or develop it as they see fit. All registry
    information (the information you provide when registering a domain) that is associated with
    active domain names is maintained and made available through the WHOIS service.

    A top level domain (TLD) is the highest level of domain name on the internet. The further
    most right label in a domain name is the TLD. In the domain name ‘example.com’ the TLD is
    ‘.com’, with ‘example’ forming a subdomain of the TLD. T wo main groups of domains exist,
    generic top level domains (gTLD’s) and country code top level domains (ccTLD’s), there are
    also other small groups of domain names.

    A domain name registrar is a service that allows you to officially register your desired
    website domain name so that it is unique to you, and no one else can own it. Originally,
    there was just one organisation that could register your domain name for you, but now there
    are literally hundreds. Legitimate domain name registrars are accredited by the Internet
    Corporation for Assigned Names and Numbers (ICANN). ICANN is a private (non-
    government), non-profit corporation that has been given the responsibility of allocating IP
    addresses and managing the Domain Name System.

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                     Website Design / Web Development / Website Production

    The Domain Name System is what allows you to reach a website by typing in its name,
    rather than its numerical IP address.

    Although you can register your domain name directly with a dedicated domain name
    registrar, many web hosting providers can register your domain as part of their web hosting
    package. This is often a more economical option than registering your domain name
    independently and then choosing a web hosting company, as that often involves a transfer

    Only consider a domain name registrar that is accredited with the Internet Corporation for
    Assigned Names and Numbers (ICANN). Legitimate registrars should indicate their
    accreditation in their Domain Name Registration Agreement or terms and conditions
    documents. You can also check your registrar's status in ICANN's Accredited Registrar

    The majority of domain registrars will register your name for a period of one year for a given
    rate depending on the services offered and the size of the company. Many registrars will
    offer a discounted rate if you register for several years at once. This can be a great deal, but
    be aware that most registrars have a "no refunds" policy on your registration fees - only sign
    up for a multi-year contract if you're sure you want to be committed to that registrar for that
    amount of time.

    It's usually more cost-effective (not to mention simpler) to register your domain with your web
    host, if they offer that service. If you register your domain with a registrar, and then choose a
    different web host, the web host will often charge you a domain transfer fee. Save time and
    money - do your best to find one provider that can handle both your domain registration and
    your web hosting needs.

Top Five Domain Registrars http://premiumdomainregistration.com/#/registrars/4542809921

GoDaddy.com http://www.godaddy.com/
Namecheap.com http://www.namecheap.com/
Name.com http://www.name.com/
Moniker.com http://www.moniker.com/
123-Reg.co.uk http://www.123-reg.co.uk/

   HTML (HyperText Markup Language)

   World Wide Web

   Browser

   ISP (Internet Service Provider)

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                     Website Design / Web Development / Website Production

 Domain Name Server (DNS)
The Domain Name System (DNS) is a standard technology for managing the names of Web sites
and other Internet domains. DNS technology allows you to type names into your Web browser
like compnetworking.about.com and your computer to automatically find that address on the
Internet. A key element of the DNS is a worldwide collection of DNS servers.

A DNS server is any computer registered to join the Domain Name System. A DNS server runs
special-purpose networking software, features a public IP address, and contains a database of
network names and addresses for other Internet hosts.

DNS Root Servers
DNS servers communicate with each other using private network protocols. All DNS servers are
organized in a hierarchy. At the top level of the hierarchy, so-called root servers store the
complete database of Internet domain names and their corresponding IP addresses. The
Internet employs 13 root servers that have become somewhat famous for their special role.
Maintained by various independent agencies, the servers are aptly named A, B, C and so on up
to M. Ten of these servers reside in the United States, one in Japan, one in London, UK and one
in Stockholm, Sweden.

DNS Server Hierarchy
The DNS is a distributed system, meaning that only the 13 root servers contain the complete
database of domain names and IP addresses. All other DNS servers are installed at lower levels
of the hierarchy and maintain only certain pieces of the overall database.

Most lower level DNS servers are owned by businesses or Internet Service Providers (ISPs). For
example, Google maintains various DNS servers around the world that manage the google.com,
google.co.uk, and other domains. Your ISP also maintains DNS servers as part of your Internet
connection setup.

DNS networking is based on the client / server architecture. Your Web browser functions as a
DNS client (also called DNS resolver) and issues requests to your Internet provider's DNS
servers when navigating between Web sites.

When a DNS server receives a request not in its database (such as a geographically far away or
rarely visited Web site), it temporarily transforms from a server to a DNS client. The server
automatically passes that request to another DNS server or up to the next higher level in the
DNS hierarchy as needed. Eventually the request arrives at a server that has the matching
name and IP address in its database (all the way to the root level if necessary), and the response
flows back through the chain of DNS servers to your client.

   Web Server

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