1. Introduction to Networks
Ms Jennifer
Ms Jennifer - Senior 2 ECDL

2. What is a network?
A network consists of a group of computers and other peripherals (printers, scanners etc.) connected to each other
Ms Jennifer - Senior 2 ECDL

3. What is the purpose of a network?
Share data with other people
Share peripherals (printers, scanners, computers)
Share programs
Communicate with others effectively
Ms Jennifer - Senior 2 ECDL

4. The Internet
The Internet consists of millions of computers around the world connected together.
The Internet may also be referred to as: the Net, or Cyberspace.
Ms Jennifer - Senior 2 ECDL

5. The World Wide Web (WWW)
World Wide Web is the term used to describe all the content that you can view on the Internet which is a global network.
All this content is saved in websites which are made of web pages.
Web pages include text, images and videos.
Ms Jennifer - Senior 2 ECDL

6. VOIP
Voice Over Internet Protocol (VOIP) enables you to communicate at real time through the Internet by using an Internet telephony.
Almost all modern telephones can be used to communicate via the Internet.
Many ISPs (Internet Service Providers) today, offer this service free of charge because the service used to communicate via VOIP makes use of the Internet.
Ms Jennifer - Senior 2 ECDL

7. Electronic mail (Email)
Through s we can transmit messages over a network.
s can contain text, and images, video or sound files as attachments.
Ms Jennifer - Senior 2 ECDL

8. Instant Messages (IM)
IM is an Internet service through which you can communicate using text in real time.
Examples of IM include chatting on social networks, like google chat, skype and Facebook.
Ms Jennifer - Senior 2 ECDL

9. Intranet
An Intranet is a private network of an organisation. Only members or employees of the organisation can access the content of this network.
When the Intranet is connected to the Internet, the privacy of the Intranet is secured using a Firewall.
The Firewall allows access to the intranet website to authorized members only.
Ms Jennifer - Senior 2 ECDL

10. The Intranet
Ms Jennifer - Senior 2 ECDL

11. Uploading and Downloading to / from the Internet
The Internet is full of resources. We can upload a file on the Internet (Web Server) to share the file with others. We can also download a file that we require from the Web Server.
Example of uploading a file: Upload a picture from your computer to your profile picture on Facebook.
Example of downloading: Downloading your task from the web page of your ECDL teacher. 
Ms Jennifer - Senior 2 ECDL

12. Client / Web Server
In a computer network the client is the computer that requests data and the server is the computer that provides the data that is requested by the client.
Server
Ms Jennifer - Senior 2 ECDL

13. Web Server Web sites are stored and saved into a web server.
That is how websites are always visible and all the content on the www is saved and stored.
Ms Jennifer - Senior 2 ECDL

14. Understanding Data Transfer Rate
Data Transfer Rate refers to the speed at which a file is transferred from one computer or device to another.
The speed at which we upload a file to the (Web Server) or download a file to our computer.
Ms Jennifer - Senior 2 ECDL

15. How to measure the data transfer rate
The Data Transfer rate is measured by bits per second.
When we transfer a file from one computer to another, the file is sent in a collection of bits, i.e. in digital form.
If the Data Transfer Rate is high, than we can transfer a large collection of bits quickly.
Ms Jennifer - Senior 2 ECDL

16. Units of measurement DTR
bps (bits per second)
kbps (kilobits per second)
mbps (megabits per second)
gbps (gigabits per second)
Ms Jennifer - Senior 2 ECDL