Transfer of Data

Transfer of Data

1. What is a Network?

   • A network is two or more computers, or other electronic devices, connected together so that they can exchange data.
   • For example a network allows computers to share files, users to message each other, a whole room of computers to share a single printer, etc.
   • Network connections between computers are typically created using cables (wires). However, connections can be created using radio signals (wireless / wi-fi), telephone lines (and modems) or even, for very long distances, via satellite links.

2. Why use Networks?

   • Easily share files and data
   • Share resources such as printers and Internet connections
   • Communicate with other network users (e-mail, instant messaging, video-conferencing, etc.)
   • Store data centrally (using a file server) for ease of access and back-up
   • Keep all of our settings centrally so we can use any workstation
   • If we use a computer connected to The Internet, we can…
     • Make use of on-line services such as shopping (e-commerce) or banking
     • Get access to a huge range of information for research
     • Access different forms of entertainment (games, video, etc.)
     • Join on-line communities (e.g. MySpace, Facebook, etc.)

3. Why not use Networks?

   • The computer is vulnerable to hackers
   • If the network breaks, many tasks become very difficult
   • Your computer can more easily be attacked by a virus
   • If we use a computer connected to The Internet…
     • We have to be careful about revealing personal information
     • We have to be careful to avoid suspect websites that might contain malware
     • We have to be aware that information found on The Internet is not always accurate or reliable

4. Internet

   • Internet is a global interconnected network of computing devices.
   • Internet is a wide concept.
   • Internet was created in 1969.
   • The first version is named ARPANET.
   • Internet comprises network of computers, copper wires, fibre optic cables, and wireless networks.
   • Internet is governed by Internet protocol.
   • Internet is hardware in nature.

5. World Wide Web

   • WWW is one set of software services running on the internet.
   • WWW is a sub set of internet system.
   • WWW created in 1993.
   • WWW has its first version named NSFnet.
   • WWW comprises of files, folders and documents stored in various computers.
   • WWW is governed by Hyper Text Transfer Protocol.
   • WWW is software in nature.