INFO 2 CH12 - An ICT System and its Components

Information and Communication Technolohy (ICT) means using any form of digital technology for the input, storage, processing and transferring of data and the output information.

Any activity or set of activities that involves input, processing and output is called a system. Examples in biology include the digestive system. the electoral system forms a major part of a democratic society.

An ICT system is a system that uses any form of digital technology; the output goes directly to a human being or into another ICT system. Examples of ICT systems include a text messaging system on a moblie phone. An ICT system is the combination of hardware and software. A typical ICT system has programs (software) that converts the system's input into outputs.

Input means entering data into the computer or other digital devices. For example, the data input could be a bank account numbers, the numbers identifies by a bar code or the pressing of a key represnting a selection of a menu choice on a mobile phone.

Processing means manipulating the input data into information in a form that is understandable and useful to the user. This might be by counting up the numbers of items purchased by a customer and adding up the amount of money owed. 

Output means presenting this information to the user or the outside world. It must be in a form the user can understand and finds useful, so it must have context. It could be printed, displayed on a screen or in another form. The output can be to a human being or to another ICt system. Many ICT systems have a number of input and outputs. They may also include a number of processes.

An ICT system consists of the following components:

• Data
• Information
• Hardware
• Software
• Procedures
• People

Data are raw facts or figures, a set of values or measurements, or records of transactions. By itself, without context, data has no useful meaning to a human user. For example, data can be the four digits representing the PIN associated with a customer's debit card or the characters representing the contents of a text message.

Information is data that has been processed or converted to give it meaning to a human being. It is data with context. An itemised receipt for a customer produced at a supermarket checkout is an example of information.

Hardware is the name given to the physical components of the ICT system. A printer and a hard disk drive are examples of hardware. ICT systems work on the basis of input, processing and output. In many systems, data is transmitted from one computer to another. The various parts of the computer can be defined as input devices, the processor, backing store, communication devices and output devices. 

The central processing unit (CPU) is where data is processed. When buying a computer, you will see the Clock Speed of the CPU, measured in megahertz (MHz) or gigahertz (GHz). Usually, the faster the clock speed, the faster the data is processed.

The computer's memory is associated with the CPU. There are two types of memory chip; read-only memory (ROM) and random-access memory (RAM). Data in ROM connot be changed and is permanently stored even when the computer is turned off. ROM is used to store the programs needed to start up the computer when it is switched on. RAM is used to store software and data while they are in use. 

The processor is housed in a box. Peripheral devices (this is the general term to describe input, output and storage devices) can be attached to the processor via Ports- the sockets that can be seen on the side of the computer. Modern computers have Universal Serial Bus (USB) ports into which a variety of devices can be plugged. With USB, a new device can be added to a computer without an adapter card having to be added. the computer does not even have to be switched off.

Processors come in variety of forms. The most common are desktop personal computers, laptop computers and personal digital assistants (PDA).

Software is the name given to computer programs. Programs are made up of thousands of instructions that actually make the computer do the processing that is required. Without software, computer hardware is no use.

ICT systems usually involve a number of procedures that have to be undertaken to make sure that the system can run smoothly. An ICT system that uses a large database will need established backup procedures to ensure that if the system fails for any reason the data could be restored. A procedure to archive data when it is no longer current is also needed. Archiving is the removing of data that is not currently needed by the system to an offline file.

ICT systems also involve people. Most data is entered by human beings - either through use of keyboard or by another device such as a touch screen or a bar code scanner. The information output by the ICT system is read and used by human beings.

A user needs to carry out general procedures such as backing up data, changing and disposing of printer cartidges and logging on to the computer at the start of a session.