Domain Name System or DNS

According to mathematics a domain is the set of values in wich a function is defined.In practical use a domain is the range in which one can exist.But a domain in the internet is the name of the website.

For example in http://www.google.com "google" is the name of the domain.All the domains that end with a .com are generally referred to as "dot-com" domains. There are several types of domains like .org(for organizations), .net(for network related) , .us,.sg,.ge,.in(location specific) domains while .com are commercial domains. However it is not compulsary that an organization should have a .org domain and similarly for the other types of domains also. But what happens after you type in the domain name in your browser window?

Resolving Host
You often see this message in the browser while the browser is searching for the website. Soon you see the website in the browser. This webpage might be coming from another continent too. These webpages are stored in webservers which can be physically located in any part of the network-Internet. Each webserver has a specific and unique IP address which is used for identifying it in the netrwork. As soon as you type in the domain name, the Domain Name System or DNS translates it into IP address. For example www.google.com translates to 74.125.19.99. You can directly type in this IP address of any domain to get the website. However, domain names are meaningful and easy to remember and that is what they are meant for.

This can be compared to the phone book in mobile phone. You type the name of your friend and hit the call button, your mobile phone dials the number of your friend and the network connects it. Here DNS(Domain Name System) is the mobile phone and the contact book need not be maintained by us and websites are still our friends.

As soon as the webserver or the host gets a request of webpage it sends the webpage to the client. Hence, a unique domain name will always be directed to the same servers and the job of the provider is to serve the requests of all the clients.

How do websites earn money: Especially Google

The answer for certain websites like amazon.com or ebay.com or playboy.com is very obvious. They provide a service through internet and they charge money for the service done.

But websites like orkut or facebook or google search do not charge for the service they offer, instead they mainatain loads of data (obviously a lot of crap) for free. Do these websites get money from what you pay (The monthly bill you get) to your Internet service provider? The answer is a straight No. Then where do they get money from? The answer is through advertisements.

The actual question is why is google earning more than the remaining advertisement companies.The simple answer is its policies and its eficiency. But, its not as simple as it seems. The clients pay the advertising company(say google adsense) for every landing on their website,i.e., for every click on their ad placed by this company. The number of clicks on the client website increases the publicity of the website. Obviously out of such number of clicks the client may get benifited by few transcations.

The task of the advertising company is to place the ads in such a place where most of the users find it when they want it.Then google started showing ads in the form of sponsored links in the search results.These sponsored results appear at the side bar or at the top of the search in a different colour. However, the remaining result is shown as is. But there are cases where the user is interested in some product only if its shown to him(i.e. he has no need to search for it) , or he is completely unaware that such kind of service exists at all. Then he would not search for it and google wants to display only relavant ads to the user.In other words the user doesn't like to see an ad of shoe polish while searching for toothpaste.

Then came the adsense, in which google pays- a part of what it gets from its clients -a user for displaying ads on his blog, a maximum a user can get for his interests. And here comes the role of efficiency where google has to display the right ad which the user might be interested in. That is adsense words. The ads are displayed according to the content on the blog. Thus the rato of transactions to the number of landings on the webiste of the client raises, giving him a good opportunity to showcase his products to a wide audience and getting returns for the investment he has put on ads.The one displaying ads is also paid(indirectly, google has hired these people) and so he strives a lot to publicize his blog and mainatain it with more interest. Blogging can no more be called a waste of time in any case.

It is the policy of google that makes the client to go for it.The client pays for the number of landings on his website.The user can click on the ads repeatedly and get some bucks.Google is very strict about such people. It also moniters where the clicks are coming from and if more clicks are from the same IP address the user is forbidden from using adsense anymore.

This involves a lot of continuous work by google and they are the leading advertising company with more places to display ads the space is increasing day by day.

The other websites earn money by placing ads on their homepage or other pages.Orkut also displays ads after the user logs in, however it is a service provided by google which might later land you up in using their other service, adsense.