Page 132 - Web Applications (803) Class 11
P. 132

was created that allocates names to some machines (web servers) and keeps a database of these names and their IP
              addresses. Domain names are the names given to these web addresses. For examples, cbse.nic.in, indianrailway.gov.
              in, amazon.com, etc. A domain name usually has the following parts:
                                          https://www.xyzwebsite.com






                                       Protocol      Subdomain      Brand domain    Top-level domain

              There are just a few hundred top-level domains available, which are separated into two groups: Generic domain names
              and country-specific domain names.

                 Generic Domain Names                                       Country Specific Domain Names
                 .com—Commercial business                                   .in—India
                                                                            .au—Australia
                 .edu—Educational institutions
                                                                            .ca—Canada
                 .gov—Government agencies                                   .ch—China
                 .mil—Military                                              .nz—New Zealand
                 .net—Network organizations                                 .pk—Pakistan
                                                                            .jp—Japan
                 .org—Organizations (non-profit)                            .us—United States of America


              Domain Name Resolution

              It is the process of determining the IP address associated with a domain name. This is how it goes:
              Let’s say you want to visit a website and type a URL into your web browser. The browser first looks for the IP address of
              the server that corresponds to the Domain Name (contained in the URL) on your computer. If this address is present,
              the associated server is contacted using this address, and the website is then shown in your browser.
              Otherwise, the browser transmits the domain name to a set of servers (known as domain name servers) that lookup
              the IP address. After the IP address has been determined, the server is contacted, and the webpage is shown in your
              browser.







                                                           Where is                            DNS root server
                         I want to go on               www.nameabc.net.?     DNS of net?
                       www.nameabc.net.                                       Try 122.34.12.19



                                                   IP of                  DNS of nameabc.net.?
                                             www.nameabc.net.?               Try 201.11.97.10
                                              It’s 202.22.21.100
                              User
                                                            User’s DNS server
                                                                                            DNS server of <<net>>
                                                                           www.nameabc.net.?
                                                                            Try 202.22.21.100







                                                                                      DNS server of <<nameshield.net>>
                130     Touchpad Web Applications-XI
   127   128   129   130   131   132   133   134   135   136   137