iGCSE Computer Science - Distance Learning

Tutor Marked Assignment 6
Tutor Marked Assignment 8 (Programming)

The Internet – Types of Network & DNS

When we discuss networks, we should be aware that they don’t always need connection to the internet. However, the internet is an example of a WAN (Wide Area Network). Understanding how the internet works also gives us an insight into how smaller networks transmit data.

The internet is made up of a global network of LANs (Local Area Networks) all connected together using routers that allow data to travel between connected devices.

Imagine that you were travelling from Norwich to Nottingham by car. You would have to follow the network of roads between the two cities going via a number of other places on the way. In the example, this could be Peterborough.

In the same way as driving between cities, data between two devices on the internet must travel usng the connected routes available, often bouncing between a number of routers before reaching their destination (although in reality this takes just a few seconds).

In order for the two devices to connect, a number of protocols are used. A protocol is a set of rules that governs data transmission and allows the devices to agree on how the data will be transferred. Usually, the data being requested over the internet is connected to a web page, like this one.


The Cloud is another name used for storage and software that is accessed through the internet. It isn’t, as the name suggests, a special area somewhere in the sky. In fact, most we servers are large computers running in offices that have been opened up to traffic from the internet. So saving your data to the cloud, is using someone else’s hard drive in a different location (although that someone else will also be responsible for backing up the data).

FTP (File Transfer Protocol)

FTP is the set of rules that allows the upload of files to a webserver using valid login details. More Revision

Web pages and the files that are used by them such as images & downloadable files need to be saved in an accessible location so that when a user connected to the internet requests access to the page, they can be sent to the user’s internet browser.

Web servers can be run on any computer with an internet connection, but because they need to alow traffic in from the internet, they are often run by technical specialists who add additional anti-virus & firewall protection to the servers.

Often people talk about buying ‘hosting’ for their website. This simply means that they are renting space on a webserver to store their website files which are then accessed using the servers IP address.

Domain Name System (DNS)

Once a website has been loaded onto the webserver, the users need a way to access the website. They do this using a URL (Uniform Resource Locator).

The sites DNS is a database of all registered URLs which matches them to the IP of the webserver.

Different parts of a site may point to different servers. For example, the website may be stored in one location, email on another, and a database on another. Using the DNS, the same URL can be used for each because of the protocol used.

The Cloud

The cloud is in fact simply using web servers to store data and access programs using an internet browser. It is an eveolution of the internet that has allowed mobile devices to be used to complete more tasks than previously possible.

Cloud storage refers to uploading files to a web server. Often this is used as a backup facility to keep files  physically safe ‘offsite’.

Cloud storage is also a useful way to access files away from a computer. For example, you may be completing your homework in a coffee shop, but don’t have a memory stick. Instead, you upload your homework to cloud storage, then log on and download a copy once you get to school.

Cloud Computing refers to software that we can access and use through a browser without needing to install any software on the computer. These are often subscription-based and users pay an annual or monthly fee to be able to access the software.

Sometimes cloud computing software is provided alongside cloud storage packages such as Google Docs that supports Google Drive, or Office 365 that supports Microsoft cloud.

Revision Activity

Download the visual Scribblit notes on The Internet as a wide area network below. Use the video to add your own definitions for the key terms and other notes.