Why not try our Mail Server or FTP Server

 

Step 1: Understand
This page explains how certain aspects of the Internet work. More experienced users can skip this step and go directly to the relevant section.


How the Internet Works
The Internet is a huge collection of computers all connected together to form the worlds largest computer network. These computers can usually be classed into two different groups, users and servers. Most likely the computer you are using now would be classed as a 'User Computer' as its purpose is mainly to access and use the Internet. However, servers are usually intended to store emails, websites and other kinds of information. Information on the Internet is mainly transmitted from one computer to another via a temporary direct connection between the two. This connection can be thought of as a water pipe, allowing data to flow from one computer to another quickly and reliably. When you access a website, send an email or connect to an FTP server, your computer will be creating and using these connections.


Establishing Internet Connections
For these connections to be possible and to ensure computers can locate each other, all computers on the Internet are assigned a unique IP address. This address works exactly like your home postal address and is intended to represent your location on the Internet and therefore allows information to be sent directly to you. When a computer is attempting to connect to another computer, there is another piece of information that is required. This is a port number. You can think of a port number like a name on top of an envelope which is used to direct the letter to the relevant person within a household. As an example, a web server checks for connections coming in on port 80. This way it knows that information on this port will be related to website information.


How Websites Work
As you already know, to visit a website you must first connect to the Internet, open your favorite browser (which you will be using right now to read these pages) and then type in the address of the website you want to visit. If the website exists, the relevant page is downloaded and is presented to you. Although simple to do, beneath the surface lies a complicated but not difficult to understand procedure of events. Here is a list of what happens when you hit the 'Go' button or press the enter key...

  1. Use the website address to find the computer where the website is located.
  2. Connect to that computer.
  3. Request the webpage.
  4. Display the webpage.

Every website on the Internet is actually stored on another computer connected to the Internet. These computers are called Web Servers and do just that: serve web pages to the rest of the world. The address of a website is used just like your home address and allows your browser to easily find the correct computer running that website. However, what most people don't understand is what happens when you press 'Go'. Websites can only work when there are 2 pieces of software in use... a web client (such as Internet Explorer) and a web server. The server simply listens on port 80 and accepts connections from web clients, sending the requested files along the connection.


Domain Name Servers (DNS)
When you type http://www.code-crafters.com into your web client... the web client uses a DNS to convert the domain name to an IP address so it can locate the correct webserver. This is similar to calling an operator and asking for a telephone number given a particular company name. There are many DNSs around the world and they all communicate with each other to keep up to date with any changes. As you can imagine, without these DNSs in place, the Internet would only be accessible by typing in a known IP address to reach a particular computer. The request would look like http://192.168.0.1 and would make it almost impossible to find what you were looking for.