NETWORKS

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NETWORKS

• Stand-Alone Machines VS Computer Networks

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Learning Objectives

• Define stand-alone machines.
• Define workstations / terminals and servers.
• List the advantages and disadvantages of
  stand-alone machines and computer networks.

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Stand-alone machines

• A computer
• cannot communicate with and is not connected to
  other computers.
• with all devices connected directly to it.

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Disadvantages of stand-alone machines

• Users cannot easily share information
• Every computer needs to be connected to a
  printer.
• With these problems in mind, it was realised at
  an early stage that connecting these computers
  together would overcome many of these
  disadvantages.

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Servers and Workstations / Terminals

• Workstations / Terminals
• A computer connected to other computers.
• Servers
• A computer that 'serves and store files for the
  workstations.
• They are often more powerful than a standard
  computer because they need to store a vast amount
  of data. 

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Computer Networks

• Advantages
• A user can access their files from any
  workstation / terminal.
• Files can be shared by users.
• Users can communicate with others on the network.
• Individual workstations do not need a printer,
  one high quality printer can now be shared by
  everyone, thus cutting costs.
• Networks provide security
• A user must have the correct Password and User ID
  in order to be able to access the information on
  the network.

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Computer Networks

• Disadvantages
• Networks can be expensive to set up
• They often involve taking up floors and ceilings
  to lay hundreds of metres of cables.
• The Server needs to be a powerful computer, which
  often means that it is expensive.
• Networks are vulnerable to security problems
• Hackers, disgruntled employees or even
  competitors might try to break into the system to
  read or damage crucial information.
• Much effort is spent preventing unauthorised
  access to data and software.

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Computer Networks

• Disadvantages
• If the main Server breaks down, then the whole
  system becomes useless and no-one can carry on
  working.
• Because networks are often complicated, they need
  expensive expert staff to look after them.
• As the number of users increase on the network,
  the performance of the system can be affected and
  things start to slow down.

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TASK B DOCUMENT PRODUCTION

• Students -- ICT -- IGCSE -- Computer Networks

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Plenary

• What are stand-alone machines?
• A computer which
• cannot communicate with and is not connected to
  other computers.
• with all devices connected directly to it.
• What are workstations / terminals and servers?

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Plenary

• What are workstations / terminals and servers?
• Workstations / Terminals
• A computer connected to other computers.
• Servers
• A computer that 'serves and store files for the
  workstations.
• They are often more powerful than a standard
  computer because they need to store a vast amount
  of data. 

12
Plenary

• What are the advantages and disadvantages of
  stand-alone machines and computer networks?

13
Computer Networks

• Advantages
• A user can access their files from any
  workstation / terminal.
• Files can be shared by users.
• Users can communicate with others on the network.
• Individual workstations do not need a printer,
  one high quality printer can now be shared by
  everyone, thus cutting costs.
• Networks provide security
• A user must have the correct Password and User ID
  in order to be able to access the information on
  the network.

14
Computer Networks

• Disadvantages
• Networks can be expensive to set up
• They often involve taking up floors and ceilings
  to lay hundreds of metres of cables.
• The Server needs to be a powerful computer, which
  often means that it is expensive.
• Networks are vulnerable to security problems
• Hackers, disgruntled employees or even
  competitors might try to break into the system to
  read or damage crucial information.
• Much effort is spent preventing unauthorised
  access to data and software.

15
Computer Networks

• Disadvantages
• If the main Server breaks down, then the whole
  system becomes useless and no-one can carry on
  working.
• Because networks are often complicated, they need
  expensive expert staff to look after them.
• As the number of users increase on the network,
  the performance of the system can be affected and
  things start to slow down.