WJEC A2 Learning Guide

HideShow resource information
  • Created by: Victoria
  • Created on: 27-02-14 12:25

Contents

1. Networks (pg 2-7) 

2. The Internet (8-11) 

3. Human-Computer Interface (12-13) 

4. Working with ICT (14-19) 

5. Security Policies (20-21) 

6. Databases (22-23) 

7. Management of Change (24-25)

8. Management Information Systems (26)

9. System Development Life Cycle (27-30)

Case Studies

  • Schools

  • Banks

  • Supermarkets

  • Hospitals

  • Lawyers/Solicitors


 

1. Networks 

Peer-to peer vs client server

Peer-to-peer each computer has the same status.  Can be used for home sharing and are popular in sharing P2P networks across the internet .

Advantages

Disadvantages

Cost saving as no server required

No central backup

No network manager required

users require more IT knowledge

Easy to set up

poorer security

No reliance on a server so no issue of breakage of the server

some computers may run slowly

lower operating costs

Users may not be able to find needed files

Users decide what files are stored (peer responsibility)

only suitable for small networks

Client Server

These are the prefered choice for large networks compared to peer-to-peer. A more powerful computer  serves  the the client terminals. All the files and programs are stored on the  server.

Advantages

Disadvantages

Security is better (1 person has admin rights rather than a hierarchy of passwords)

More expensive  - servers are expensive

Centralised data all users have access to the same set of data

Need specialist knowledge to maintain

Backups are taken centrally

Software is specialised sophisticated and expensive

Faster access to programs as the server is  more powerful than Peer to Peer

if server breaks the network is unusable

Centralised administration


 


 
 
 
 

Network Topologies - Physical configuration of a network, which shows how it is linked together

Ring

No central computer, computers are all linked to one another.

Advantages of ring
  • Network not dependant on central computer

  • Each computer has the same access as the others so no one computer can hog the network

Disadvantages of ring
  • If there is a break in the connection then the whole network fails

  • Faults are difficult to locate

  • It is impossible to keep the network running whilst equipment is added or removed, because there is only one path for the data to follow

Star

All computers connected to a single point such as a hub or central powerful computer

Advantages of star
  • Fault tolerant – if one of the cables fails, then the other computers can still be used

  • Load tolerant – extra computers can be added without much loss in performance, because all computers have their own path to the server

  • Easy to add extra computers – extra computers can be added without disturbing the network

Disadvantages of star
  • Higher cost – the large amount of cabling needed makes it more expensive

  • Dependence on the central server

Factors for Choosing

Cost
  • Cost can include the cost of the server if relevant, cabling, and software and third party communications services.

  • For smaller organisations cost can be a limiting factor but for larger organisations, cost is not normally an issue.

Comments

No comments have yet been made

Similar ICT resources:

See all ICT resources »See all resources »