What is an Ad-hoc network ?

Ad-hoc network

           An Ad hoc network is a computer-to-computer network, or in more advanced terms a peer-to-peer network. The word "ad  hoc" is a Latin word, which means "For this purpose", which means for a special purpose.
      It is usually a temporary network established between two or more computers, for special purposes such as network sharing, file sharing and devices such as printer sharing. It may be temporary or permanent.

How it works?

     
        Its working is simple. If one computer has internet access, then it can share it with other computers. Unlike Wi-Fi, it does not requires a router or any Base station, thus it can also be called an "infrastructureless" network. It is simply a network between a group of computers. Suppose a computer has LAN or WLAN any kind of network access, and it has another wireless adapter or Ethernet port which is currently not in use. Then, with the help of wireless adapter or the Ethernet port, it may share its network from its LAN or WLAN, on wireless adapter or Ethernet. Then other computers will be able to access internet wireless or wired, depending on how it is being shared.
       In simple terms, it is the sharing of data to and from two or more devices. In adhoc network each mobile device or any device with wireless capability connected to the network acts as a router.

Almost all operating systems support an ad hoc network. It is very easy to create one.

The other computers or devices must be in range of the host computer/device for an adhoc networks to be created.

What is DNS ?

DNS stands for Domain Name System, not Domain Name Server. It is a protocol or a set of methods and actions which defines everything happening from the requesting of a webpage by a client, through the conversion of domain into IP address and the processes taking place in server, to the providing or redirecting of client to the requested webpage. It is a short and easy summary of DNS. But it should be noted that the files and webpages are not transferred by DNS, in fact only their addresses are transferred.

Steps involved in DNS

The Domain or URL

First the client or user requests for a webpage in a web browser. The syntax of URL or Domain which is entered in the address bar of the web browser is something like this:
A domain name consists of several parts called labels. The are separated by dots, such as www.rustedbyte.blogspot.com .
The right-most label is called top level domain. In the above example .com is the top level domain. The other labels to the left of top level domain are called subdomains or subdivisions of the top level domain.The subdivisions may be up to 127.
Any label may not start or end with a hyphen.

Conversion of Domain or URL into IP address

Through DNS, the Domain, web address or URL you have entered is converted into its IP address. For example, google.com has IP address : 173.194.124.39 .
  You can find out the IP address of almost any website by pinging. Just open command-prompt, or cmd.exe. And the use ping command, such as:
        ping rusted.blogspot.com
You can use the IP address to open a website by just entering the IP address into the address bar.

IP address gets transferred to server

The IP address gets transferred to a server, usually ISP's server. The server looks up for the IP address in its memory, if found then it will redirect the client to the server which is hosting the requested webpage. If not found then it will transfer the requested address to another server, if that server knows the address of the server which hosts the requested webpage, then it will transfer required info to the ISP's server.

Caching of the webpage's server's address

If the server which gets the clients request, already has the requested webpage's hosting server's address, then it will just redirect the client to the requested webpage. If not, the above step will take place. After getting the address from another server, the ISP's server will cache the address or store it in its memory, in case there are more requests for the same webpage.

Back to the client

The client gets redirected to the requested webpage.