Perhaps one of the most well known parts of the entire web is that of the computer network. By definition, a network is nothing more than a group of connected computers. This can be your personal computer or laptop being connected to the servers at Google. When the connection is made, a network is created. Of course it is a little more complex than this and there are also a variety of types of networks one can connect to.
The network is the basic component which is necessary for the internet to occur. Through it a series of computers whether they are personal or servers can communicate to each other. It was back in the late 1960 when the world very first network was established. This network was known as the Advance Research Projects Agency and through the operations of this US government controlled agency, the Advance Research Projects Agency Network or ARPANET for short was born. Of course through technicality, if you are looking at this webpage and are not sitting in front of the server that hosts it, then you are making use of the ARPANET, well at least what is left of it. Through time and advancements in science as well as collaboration by a number of known characters such as Tim Berners-Lee, the World Wide Web Consortium would be born and would take over control of ARPANET in order to create the internet we know and use today.
Networks are not just the internet as there are many different types out there. These can actually be classified by their scale with the smallest of course being the Local Area Network or LAN. A local area network usually is composed of the computer you are on now and any others that may be in your home, plus the actual modem or any routers. All of these are interconnected via a LAN card and twisted pair wires. However the modem may also be connected to the phone line, the cable or even a fibre optic backbone.
In the case of a larger scale network, but not quite your ISP, you have the WAN or Wide Area Network. Keep in mind that some ISPs can be a WAN, but in most cases they are a Metropolitan Area Network or MAN as a WAN can cover many different metropolitan areas. After these two you also have the Personal Area Network as well as the Virtual Private Network which are usually fairly small and also somewhat secure connection between several or many hundreds of computers.
Connection into these networks can also occur in a variety of ways. The first of which was stated before which is the use of the Ethernet or LAN card which is connected from computer to computer via some form of router and twisted pair wires. You also have the Wireless LAN which if you remember is a wide area network.
Then we have to also discuss the concept of architecture. Not all networks follow the same architecture. The biggest example of this is the differences between the World Wide Web and Peer to Peer networks. Both of these are networks, but they communicate in completely different ways. In general, all computer networks are classified by what is known as topology. These topologies can be things such as a Bus network, a mesh network, a ring network or even a star network. Each one of them is different and each one serves its purpose efficiently as possible. Keep in mind, that the concepts of these can be fairly self explanatory. For starters the bus network is basically piggy-backed from one client to another like a bus running its route through your city. Star and ring networks too are self explanatory whereas a star network as a single central computer and all communications go through it where as the ring network requires one computer to connect to another computer through a series of jumps between the others in the ring.
Of course while these are fairly self explanatory, they can become much more convoluted. This concept of topology goes on to discus redundancy and number of hops to make a connection. When one computer wants to connect to another one, it has to send out a request to another computer and then so on and so forth until the request is confirmed and the connection is made. In the concept of a mesh network, there are no hops because the network is redundant in the fact that every computer in the network is connected to every other computer.
However, when it comes to the internet, this cannot be a mesh network even though you may be connected to such a network through your ISP or company. In order to connect to a website, a request has to be sent through a DNS or domain name server who then connects you with the proper server. There may also be another connection depending on whether that website is sharing a server with others. The signal is then sent back along this same route which is why one develops latency in their connection. This can be a very serious issue for some people in other countries. For example, anyone in the Philippines who uses the internet, even if connecting to a locally hosted website has to go through their ISP’s DNS which is in the United States and then back. As a result, the average internet user in the Philippines whether they are connected to a fibre optic line or not has an average of more then 750 milliseconds of latency in their internet connection. Original Authors: Nick
Edit Update Authors: M.A.Harris
Updated On: 30/01/2009