There are 2 sides to web site. There is the domain and there is the server. The domain is a nickname stored in the database that tells the browser where to go. The server is the actual machine that delivers the client. Read more to find out how this process works.
1. Domains
One day back 1997, the founders of Google, Larry Page and Sergey Brin, set up an account on a domain registrar and told it that their website will be called "google", and it will end in ".com", thus creating the domain google.com.
All the domains are stored in a directory service maintained by "domain registrars". Your browser knows where these places are, and when you tell it to go to google.com, it will first go to the registrar service, find where the actual internet location is, and then go to the actual internet location.
Why did the Google founders want to do that? It'd be a lot easier to just eliminate the middleman and tell people to go their site directly. They did this because the actual location of their site is impossible to remember. Google's true internet location is actually:
If people had to type that out every time they wanted to visit Google, then nobody would ever visit Google. This is the sole reason the domain system was invented, and why domains are important. Instead of memorizing 4 seemingly random numbers, we can just memorize the name "google".
This also has a side benefit of helping you if you move. When you put your sever in a different place, you location changes. This would be quite annoying if you had a millions of visitors that already know one location. Google now only has to update their domain listing, and when browsers asks where they are located, they'll go to the new place.
It's possible to have a domain that doesn't go anywhere. People do this because domains are first-come, first-serve, and they want to grab them before someone else does. A really good domain can resell for millions.
2. The server
If don't want your domain just floating around in cyberspace, then you need a computer (called a server) with an internet address (called an IP address) to direct the browsers that ask it where to go.
This is where hosting companies come in. Google has a computer sitting at internet address 72.14.207.99. It is very fast, and it has a very fast internet connection. It is on 24/7/365, and ready to be swapped with another computer just as fast if it ever needs to be shut down.
If their site did go down, then this is what you'd see:
People can't reach their site, and Google's entire business model is based on people being able to reach their site. This is why Google spends a great deal of resources to ensure their web servers are always on. This process of maintaining a computer to allow users access it through the internet is called hosting.
Most people don't have the time nor energy to invest in a computer running all the time with a fast internet connection, and they'd rather not deal with all the security and reliability issues that go with such a system. Therefore, they will instead hire a hosting company, and then point their domain to them. Now, the web master can perform all the updates and development at home or through a web browser, and the hosting company will keep it running 24/7/365, and their price will be for much less and more secure if the web master tried alone.
Now that you know how it works, if you'd like to know tips on how to find a good hosting company for your own site, we recommend reading How to Protect Yourself
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