So what is this Internet thing?
How Information moves across the 'Net
The Origins of the Internet
Who Controls the Internet?
Related Documents
The Internet Explained
The internet is a vast communications network covering the globe (and also beyond with the integration of satellite communications and the ability to communicate with vehicles we send into space!).
It can be best thought of as a large collection of nodes (this is not a technical term, just one that I use to illustrate the structure of the internet) connected by a web of different communications technologies. These technologies include physical wires, satellite communications, wireless radio communications etc..
The internet is made up of many thousands (or even millions) of these nodes which may themselves be smaller networks or may be individual pieces of equipment. What each of these nodes has in common is that they have the ability to receive messages sent to them, and pass the messages on if not intended for them.
This is essentially how the internet works. Information is sent into the internet with a destination attached to it. The information will be received by a node which will check to see if it's the intended destination. If not, that node will pass it onto another that it is 'connected' to. This next node will check to see whether it's the intended destination, and if not will pass it on. This process continues until the information reaches it's destination.
No individual node knows about all the other nodes that make up the internet, they only know about the other nodes close to them, but this is enough to allow information to pass across the internet.
The process of deciding which node to pass information to is much more complex than my description and depends on various factors. If you want to know more detail there are many good books available that explain it.
How Information moves across the 'Net
Suppose you are sending an email with a large attachment to someone over the internet. It would not be practical for all this information to be sent as one long stream - the internet solves this issue by breaking up all the information into packets.
A packet is a small chunk of information, that also includes network data such as the destination and the sequence number of the packet.
So, the information is split up into many packets which are then all sent individually to the destination. If you think about the way the internet works, you've probably guessed that these packets aren't all going to take the same route to get to their destination - in addition, if there are problems and any of the packets are 'lost' they will have to be automatically resent by nodes on the network.
The result of all this chopping information up and sending via different routes is that the packets are unlikely to arrive at their destination in the same order they were sent. So if five packets are sent in the sequence 1, 2, 3, 4, 5 they may arrive in sequence 3, 2, 5, 1, 4 - obviously, not ideal for understanding the information at the destination!
The destination computer will collect the packages, reorder them, strip the data that's been added for transport across the internet and then 'stitch' the packets back together, in the correct order.
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The Origins of the Internet
In the 1960's the American Defence Department commissioned a company called ARPANet to design a method for sending information in a way that would be protected from nuclear attack.
This resulted in the earliest form of the internet. The fact that information is sent from one node to the next means that there is no route planned for that information. This means that should nodes become unavailable, the information will just be sent to other available nodes, avoiding any 'holes' in the network - exactly what was needed if parts of the network were destroyed!
In it's earliest days the internet was just used to connect military, academic and government organizations, however it soon grew.
Email was a very early application of the internet, although everything had to be sent as text (pictures had to be manually encoded and decoded to be sent as email).
When a research lab in Geneva called CERN developed the first web browser (Mosaic) the World Wide Web was born. This enabled people to view information as more than just text and since this time the growth of the internet has been phenomenal!
Who Controls the Internet?
Understanding the nature of the internet includes understanding that it is made up of many thousands (or millions!) of smaller networks, all connected together in a giant mesh.
These individual networks belong to a vast range of organizations ranging from private individuals, companies and governments across the planet. So, since the internet is made up of all these smaller networks, and since all these networks can be owned by anybody, there is no one party owning or controlling the internet.
This is one of it's greatest strengths, since no government or other body can control or limit the information available on the internet.
However, this is also one of it's main weaknesses and there is a lot of concern about the ability to access 'bad' or illegal information - the internet has no borders!