INTERNET Communications & Networks

The Internet èThe Internet is a Wide Area Network that covers the entire world èIt can be thought of as many different, smaller networks connected together. èA vast quantity of information is available on the Internet. Mostly on web pages but there are also a huge number of files available for download.

The Internet èThe Internet provides three main services: èThe World Wide Web, which gives access to databases through browsing or searching èElectronic Mail, which provides one to one (or one to many) communication and exchange of information. èFile Transfer, which makes it possible to send and receive large amounts of information.

Internet Ready Computer èAn Internet Ready Computer is a computer which can be online to the Internet within minutes of switching it on. èIt comprises: èA normal computer system èA Modem – This is a piece of hardware that allows your computer to send and receive data over a phone line èBrowser – A program designed to let you view pages on the internet (Internet Explorer or Netscape Navigator are two examples of browsers. è program such as Outlook or Eudora

World Wide Web èThe World Wide Web (WWW) is only part of the internet. èThe Web is made up of web sites, each of which contains web pages èWeb pages are connected to other related pages using hyperlinks. When you click on a hyperlink you are taken to another web page. èAny Web page can be accessed directly if its full web address or URL is known. èWeb pages are written in a special language called HTML (Hypertext Markup Language)

HTML Example HTML Web Page

World Wide Web èWhen you load a web page, you are downloading a description of what the page should look like written in HTML èIt is up to your web browser to take this information and use it to display the web page correctly. èA browser allows pages to be saved and printed and can move backward and forward through pages already accessed. èA browser also stores a history of recently viewed pages and can remember web page addresses by using bookmarks or favourites.

Connecting to the Internet There are two main ways of connecting to the internet: èDial-up connection èYour computer uses a normal phone call to connect to the internet using a modem èThis type of connection is very slow èIt also ties up your phone line so you can’t make or receive calls.

Connecting to the Internet èBroadband connection èBroadband connections are high speed connections to the internet. They can be over 10 times as fast as a dial-up connection. èADSL (Asynchronous Digital Subscriber Line) uses normal phone lines and a broadband modem. (Asynchronous because you receive data much faster than you can transmit it) èA Broadband connection is always connected to the Internet. èTelephone calls can be made and received at the same time.

Online / Offline èA computer that is connected to a network is said to be online èWhen it is not connected to the network it is offline èUsing a dial-up connection, you usually only stay online for a short period at a time. èBroadband connections are ‘always on’ which means that you can remain online almost permanently.

èTo connect to the internet, you have to use a company called an Internet Service Provider (ISP) èYour computer connects to the ISP’s computer èThe ISP has a direct high speed connection onto the internet. èYou access the internet through the ISP. èThe ISP usually gives you an address èThey will often also give you some space on their server for you to create your own web page. Internet Service Providers (ISPs)

èNormally to use an ISP you pay a monthly fee èSome ISPs don’t charge you by the month, but instead charge for the phone call when you connect to them. Internet Service Providers (ISPs)

Search Engines èThe World Wide Web contains millions of pages, on almost any subject imaginable èThere is so much information that it is often quite difficult to find what you are looking for.

Search Engines èSearch engines are big databases of web pages that you can use to find a page containing information in which you are interested èTo use a search engine, you go to it’s web site and enter some keywords into a search box. èThe search engine will then return a list of web sites that contain those keywords

Search Engines èOften, a simple search will return many pages that are not really relevant to you. èA complex search allows you to include many different search criteria which should cut out most irrelevant web sites èyou can use conditions like AND, OR, NOT èYou can restrict your search to certain domains. èSearching only.uk would search only uk web sites

Downloading Software èThere is a large amount of software on the Internet that is available for you to download and use on your computer. It falls into several different categories.

Downloading Software èFreeware – This is software that you may download and use free of charge èShareware – You may download this and use it for a trial period. After this you must register the software, usually by paying the author a fee. èCommercial Software – You can buy some software online using a credit card and then download it to your computer

Mobile Internet Technology èIncreasingly, people are using the internet from palmtop and laptop computers, to read and access the world wide web. èPalmtop computers can often be connected to a mobile phone which is then used to connect to the internet. A Smartphone

Mobile Internet Technology èA smartphone is a PDA with a built in mobile phone. You can use it like a normal phone and also access the web and with it. èPalmtop computers and mobile phones use different operating systems and wireless application protocal (WAP) browsers to connect to the WWW. A Smartphone

Video Conferencing èThis can be used to conduct a meeting or conference between two or more people in different places. èIt requires a computer system, web cam and a network connection between everyone involved.