Application and Implication of Information and Communication Technology

Information Systems

We need systems in almost every aspect of human life to prepare meals, maintain cars, travel to work or school and so on. An information system, however, is responsible for the collection, processing and overall management and distribution of Information.


Computers and communication devices are used to do this. They manage large amounts of information at a faster rate than manual systems can; such as filing, sorting and mailing. When choosing a computer information system for a particular application, you need to consider these factors:

• what hardware is used, such as input, storage and output devices
• what software is used, including the choice of custom-written, general purpose and specialized software
• what processing takes place
• what human-computer interface is used
• which people are involved and what do they do
• most importantly, what data is required.

The advantages and disadvantages of computerized information systems are as follows:

Advantages

• save enormous amount of paper and filing space.
• Rapidly find, calculate and sort data.
• Work automatically.
• Data can easily be imported from another system or program
• Data can easily be entered (by keyboard or scanner) or updated.
• Data can easily be exported (moved) from one system or program to another.
• When computers are linked together in a computer network, more than one person can access the information at the same time.

Disadvantages

• Some systems can be complicated and/or require a lot of time to be spent on staff training.
• The computer(s) running the information system may not work due to an electrical failure or a hardware/software fault. If everything is computerized, no work can be done at these times.
• Data may be incorrect.
• Some people may attempt to access confidential information. Therefore, security is extremely important.

Types of Computer System

Computer information systems can be chosen to suit different users and tasks.

• Single-user: only one person at a time can use the computer system and have access to all the computer's resources. Examples of operating systems for single users are Windows 2000 and MS DOS.
• Multi-user: many users can access the computer system simultaneously, each having different access rights and share the resources. Multi-user systems usually require user names and passwords. Example of operating systems for these are UNIX, LINX, and Windows NT.
• Single-tasking: only one program can be used at any one time. While that program is running, it controls all the system resources, even if it does not need them.
• Mulit-tasking: a method of organizing computer systems so that several different tasks or applications can be accessed at the same time. The processor divides its time between tasks. While a user is entering data at the keyboard, for example, the processor will be dedicated to a different task - there is no point at which the processor is simply waiting for (slower) input to be completed.

There are also different types of computers, each with unique characteristics.

1. Mainframe Computer

20 A mainframe computer is a computer system with:

• very powerful processors
• lots of backing storage
• large internal memory.

Mainframes are designed to process large volumes of data at high speed. They are used by large businesses such as

• banks and mail-order
• companies as well as by large
• organisations such as universities.

Mainframe computers can also multi-task by running more than one program at the same time time. This is known as multi-programming and with more memory has become possible on desktop and laptop computers.

2. Desktop Computer

A desktop computer is the most common kind of PC. It is a collection of a number of different hardware devices. This type of computer is sited permanently on a desk because its design means it cannot be easily moved. The common components of a desktop PC are:

• the system unit containing the processor and main memory
• monitor
• keyboard
• mouse
• hard disk drive
• floppy disk drive
• CD/DVD drive
• speakers.
  
  

  3. Portable Computers e.g. Laptop or Notebook Computer

  A laptop computer is a small, light computer that you can easily carry about with you. It can be powered by battery or mains power. A laptop computer has a keyboard, and comes with specialised input devices, for example trackballs, touch pads or track points. They are needed because laptop computers are often operated in places where it is impracticable to use a mouse.
  For output the laptop has an LCD or TFT screen and a set of small speakers.
  
  ‘Laptops’ are often as powerful as desktop computers and run the same range and type of software.
  
  
  People use laptops for working when they are on the move, going to meetings or attending courses.
  Many businesses are replacing desktop PCs with special plug-in workstations designed round laptop computers because of the of the flexibility they offer.
  

  4. Network Computers

  These includes network servers, such as file servers, print servers, mail servers, web serves. These machines are built for reliability  but their specification will depend on their use. For example, files servers may have very large backing store size for file system but may only require a small primary store for the operating system. Servers are not usually accessible directly by anyone except the network administrators but rather provide services to other computers when required. Servers are often more expensive than personal computers and are housed in secure environment. They are not as big and specialized as mainframes.
  

       5. Supercomputers

  these are dedicated mainframes that may be specifically designed for tasks such as performing highly complex and repetitive calculations. They have huge memory sizes, they are very expensive and are complicated to use and maintain. They often have own unique operating system and will require users to write their own programs for their use. The Cray T3E supercomputer is used to predict weather patterns. 
  
  
  References and Further Reading:
  
  Blades, Ronald & Gay, Glenda (2005). Oxford Information Technology for CXC CSEC: Application and Implication of ICT. (p. 71& 72)
  
  Johnstone High School (2003). Computer System: Different computer systems. Retrieved from
  http://jhigh.co.uk/ComputingSG/ComputerSystems/CS_Types.html