What is the Internet?

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2 What is the Internet? The Internet is the term used for inter-network. It refers to millions of small computer networks that are brought together to form the internet. The term inter-network did not catch on, so it was shortened to internet. People often mistakenly believe that the internet consists purely of the world wide web (www), but it is also made up of and messaging systems, research databases, forums and discussion groups. The world wide web makes up a large part of the internet. This part of the internet consists of websites that have one or more webpages. You access these webpages using a web browser (e.g. Internet Explorer, Firefox, Google Chrome). Later in the course, we will be looking at how to create webpages and websites, and how to connect these to the internet. It is important to remember that the internet and world wide web are not the same; the world wide web is one part of the internet. In order to connect to the internet, you must do so via your internet service provide (ISP) this is the company you have your internet connection with (e.g. BT, TalkTalk, Sky). Your internet service provider is connected to other networks which make up the internet when you connect to your ISP, you become part of that larger network. No one actually owns the internet due to the fact that it is made up of individual networks that are linked to it. However, users of the internet do have to obey certain laws and guidelines in order to access and use the internet.

3 Connecting to the Internet In order to connect to the internet, the following are needed: A computer Telephone line / cable connection Modem and / or router An Internet Service Provider (ISP) A web browser (e.g. Internet Explorer, Google Chrome, Firefox, Safari) As discussed above, common internet service providers include BT, TalkTalk, Sky and Virgin Media there are however many more. Most service providers include the same basic features access to the internet, an address, and web space (space to store your own website). In order to view webpages you need to use a web browser. Like internet service provides, all web browsers come with similar features, which include: Forward and back buttons to allow users to move between web pages quickly A stop button if a page is taking too long to load A refresh button to reload a webpage Bookmarks to allow users to save a link to a webpage they want to view again later. Favourites to store webpages that the user visits frequently Ability to print web pages A history folder which keeps a record of recently visited web pages. Connections to the internet are either analogue or digital. We will now look at the different types of connections:

4 Connections Dial-Up A dial-up connection involves a modem converting a digital signal sent from a computer, into an analogue signal which is sent through a telephone line to the internet service provider. This is then converted back into a digital signal which can be understood by the computer. When a person connects to the internet using a dial-up connection, they cannot use their telephone for phone calls. By the current connection speed standards, dial-up connections are very slow (around 56Kbps), this typically provides a download speed of around 5Kbps). Dial-up connections can also be very unreliable the connection can easily drop and may be affected by attempted incoming telephone calls. Integrated Services Digital Network (ISDN) ISDN connections are more reliable than dial-up connections and provide faster speeds (up to 64Kbps single channel or 128Kbps dual channel). It can achieve these speeds as it does not need to convert digital signals to analogue signals before sending them through a telephone line. ISDN connections require a terminal adapter; this is usually referred to as an ISDM modem. Asymmetric Digital Subscriber Line (ADSL) ADSL connections provider much faster speeds than dial-up and ISDN connections; high speed internet connections are called broadband connections. An ADSL connection can provide speeds up to 24Mbps and

5 still uses a telephone line. In order to connect to the internet using an ADSL connection, an ADSL modem / router is required these are usually provided by the internet service provider at the time of installation. ADSL connections have a further advantage, in that the telephone line can be used for calls whilst using the internet. ADSL connections can be affected by different phone lines. These lines were designed for voice signals, rather than data signals and therefore the signal quality can vary when used for transmitting data. The distance a person lives from the telephone exchange can also impact upon connection speeds. The limit for ADSL technology is 4 Km connections between a person s house and the telephone exchange beyond this distance may not work. Cable Cable connections do not use traditional telephone lines in order to provide access to the internet. Instead, they use a combination of fibre optic cables and co-axial copper cables. This means that internet service providers using these connections, can provide speeds of up to 50Mbps. Cable connections require the use of a cable modem/router which is usually provided by the internet service provider at the time of installation. Due to cable connections not using the telephone line, telephone calls are unaffected. This is growing in popularity with providers such as BT and Virgin Media being the most common cable internet providers. It is however, not yet available in a significant number of areas, but there are plans for it be made available everywhere soon.

6 Comparing Download Speeds The speeds discussed over the previous pages can be difficult to understand in practice. As a rough guide, downloading a film using a dial-up connection would take around 28 hours 30 minutes; using an ADSL connection this would take around 11 minutes. Downloading a song would take around 12 minutes using a dial-up connection and just 6 seconds using an ADSL connection.

7 Assignment 1 1. Define what is meant by the term internet 2. What is the difference between the World Wide Web and the internet? 3. Summarise the different methods of connecting to the internet 4. Outline what you believe to be the five most significant developments in the history of the internet. 5. What does ISP stand for? What is their role?