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Home : Introduction : Next Tutorial Introduction: The Internet and BeyondWhat
is the internet? The internet is quite youthful if we compare it to other forms of mass communication - print, telephone, and television included. But it is a child that has had a phenomenal rate of growth, being accepted internationally since it's conception in the sixties. Interestingly, although the terms internet and world wide web are used synonymously, they actually refer to two seperate concepts. The internet began it's life as ARPANET (Advanced Research Projects Agency Network), an attempt by the US Defence Force to share it's research and hardware resources over a wide area network. With the Cold War mentality of the time, it was also a national security measure, in that the flow of vital information was not wholly dependent on one particular network. If part of the network was down, for whatever reason, perhaps even a nuclear attack, the continuity of the country's defence system would be ensured by the other member systems. A case of not having 'all your eggs in the one basket'. ARPANET created great interest in other government centres and soon they and specialised individuals were connecting to this expanding system. It was apparent in the early years that many networks were not 'getting on' due to the wide range of manufacturers involved - IBM, DEC and Unisys to name the major defence contractors. These systems needed to be able to communicate with each other, to speak the same language in fact. In 1982 this was addressed by the implementation of a protocol called TCP/IP or Transmission Control Protocol/ Internet Protocol. At the same time, the word Internet came into general use as this was a combination of the phrase interconnected networks. It is this protocol that has given the internet it's global reach - without it, networked systems would still exist, but would not have the ability to find each other and share information. With TCP/IP every computer on this international network has a unique address. Similar to the postal system delivering a letter to your home address, each computer on the internet needs to be able to locate other computers around the world and this is done through the use of IP addresses. This address appears as a group of numbers - 207.87.249.122 is an example. These numbers are fine for number-crunching computers, but they become more than a little awkward for humans to memorise and use. To facilitate the spread of the internet into the corporate and domestic world, the Domain Name System was introduced, providing us with more information than numbers alone would give. Looking at the Monash address - www.monash.edu.au - we can break it down for a closer inspection.
Domain Name Servers and IP Addresses These Domain names are mapped to their corresponding IP addresses by Domain Name Servers - particular computers on the network that act as filter points for other computers searching for Domains, rather like giant post offices. By typing in www.monash.edu.au you are actually querying a DNS machine for the IP address of Monash so that the network computer you are connected to can find it - if the local DNS has no record of www.monash.edu.au it will in turn query another DNS machine elsewhere on the internet, which may in turn query other DNS machines. Of course, you do not see this flurry of activity, your network computer is given the IP address corresponding to the name you typed, it fetchs the data, feeding it to your browser and the Monash site will load, all being well. If all is not well you may receive the following error
This simply means that none of the DNS machines queried have ever heard of www.monash.edu.au. Either this URL (Uniform Resource Locator - the address of a web page) is spelt incorrectly, no longer exists, never did exist or is so new that it is not yet listed. Anyone can purchase a domain name but certain conditions must be met with AUNIC (Australian Network Information Centre) in Australia or InterNIC (Internet Network Information Centre) internationally, bodies that monitor internet address schemes.
In 1991 a program named Gopher was created as a means of retrieving information from the net and although it became popular, it was soon eclipsed by the arrival of the World Wide Web in 1992. This was the beginning of incorporating graphics and more pleasing formatting with the concept of hyperlinks. But access to and use of the internet was still firmly in the hands of a select few and it was not until the release of the web browser Mosaic in 1993 that it's growth expanded beyond anyone's dreams. Soon the web browser became a marketable piece of software, spanning many different operating systems, with Netscape Navigator claiming a firm foothold until 1995 when Microsoft launched Internet Explorer. What we now term the WWW is merely one of the services the internet is able to provide, others being email, FTP (file transfer protocol - transferring files between computers) Usenet (public forum news groups or discussion lists), Gopher (still around today) and Telnet (a unix program allowing access to remote machines). The Web is really referring to the web pages we browse and download. Browser software interprets data and displays it on screen - as mentioned above, the main browsers are Internet Explorer and Netscape Navigator. Browsers must 'talk to' Web Servers, which hold the requested information - usually in the form of web pages - and do so using another form of protocol, or language - HTTP (Hypertext Transfer Protocol). Hence the http:// you see in front of URL's. The rapid growth of the internet will continue as it's benefits are realised and enhanced with more multimedia content, faster download times and the price of access and computer hardware falling to levels that more middle and lower income families can afford. The diffusion of information that it has facilitated has both positive and negative aspects: 'bad' information spreads as quickly as 'good', and who determines what is good or bad? As is the case with many countries, the Australian Government is concerned with attempting to regulate content on the internet, but as it is now a massive system not owned by one particular body, having expanded beyond the boundaries of 'ownership', this appears an impossibility. It's appeal to 'the man in the street' has perhaps been it's most basic function - the ability to self-publish to a theoretical audience of millions. Anyone can create a webpage, on any topic and publish it to the Web at very little expense. And most people with an internet connection do so, if only to display a photo of their pet dog or extol the virtues of their favorite hobby. Through this course you will learn the basic fundamentals of creating a web page via HTML. There are many software products, such as MS Frontpage, Sausage Software Hot Dog, and Macromedia Dreamweaver, that allow you to bypass having to learn HTML. These do much to remove the tediousness of coding by hand, particularly when time is short, or you are working on large or team projects, however you will find that by learning some basic coding you will have greater control and will gain an understanding of the way web pages work. This is particularly useful when problems are encountered - you will be able to view your own source code and 'read' it. In the following lesson you will discover exactly what HTML means and what it can do for you. This tutorial series was authored by Wendy Phillips It is copyrighted which means you may not pinch any of it |