We talk about a computer-network when computers are connected to each other and each computer can send and receive data.
The internet is not a software-programme like e.g. MS Word. It is sometimes described as a "living organism" as it is changing permanently.
The fascinating thing about the internet is, that there is an enormous amount of information available and that you can reach people all over the world.
In some parts of the world, the internet is the only reliable method for transmitting information. E.g. in 1991 there was one single internet-provider in the Sovjet Union, who had a link to Finland and from there he could reach the rest of the world.
The ARPANET started with 3 computers in California and 1 computer in Utah, but the net grew bigger and bigger in a very short time.
The most important thing concerning secure and reliable networks is the dynamic routing. That means, if one connection is disturbed, the route will be changed automatically so that the data will reach the computer that is supposed to be reached.
During the Gulf war in 1991 the US military had great difficulties to destroy the network of the Irakis who owned network-routers with standard-internet-routing.
The ARPANET was so successful that each university of the USA wanted to join in. But that meant that the adminstration of the net got more and more difficult.
Finally it was divided into 2 parts:
But these two networks were still connected - connected via IP (Internet Protocol). The term "internet" first came up in 1982, when the internet protocol started.
Technology finally was the reason that the number of computers (PCs) connected to the ARPA Net grew bigger and bigger.
In the early 1980s, the ARPANET grew into the early internet, a group of linked networks connecting many educational and research sites funded by the National Science Foundation along with the original military ones.
The National Science Foundation developed a new, much faster network, the NSF Net, that worked excellently and many users changed from the ARPA Net to the NSF Net. In 1990 the NSF Net had so many users that the ARPA Net was closed down.
In 1994 several commercial internet-networks were developed (eg. IBM, Sprint). As the NSF Net could only be used by the staff from universities or educational institutions, but the commercial networks could be used by anyone, the NSF Net was finally taken over by commercial networks, which are run by familiar companies (eg. AT&T, IBM) or by specialist companies like Exodus networks. No matter which one you are attached to, they all interconnect, so it is all one giant internet.
The WWW is a whole lot of websites, linked together all over the world. The interesting thing are the hyperlinks, as each link leads to another website. The WWW combines text, pictures, sound and animation and lets you move around with a click of your computer mouse.
Hypertext: can be present at different places at the same time.
The WWW was developed by Tim Berners-Lee, who developed HTTP (Hypertext Transfer protocol), HTML (Hypertext Markup Language) and the URL (Uniform Resource Locator).
PC Software (Browser), eg. Netscape Navigator, Internet Explorer... Modem or ISDN Telephone connection Provider (eg. Compuserve, AOL, T-Online, ...) Tools (special software), that help you searching in the net like search engines
Be aware ...
The internet is not as private as you may think. Your email can be read by other people like a postcard you send!
And don’t forget: One computer communicates with another computer: do you really know, what they are talking about?
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