ICT

ICT systems and their usage

The GCSE ICT course is all about ICT systems. You need to know the general structure of information systems, and how they work; the role of input, output, processing and feedback; and the integration of ICT devices and ICT information systems.

What is an ICT System?

An ICT system is a set-up consisting of hardware, software, data and the people who use them. It commonly includes communications technology, such as the Internet.

ICT and computers are not the same thing.

Computers are the hardware [hardware: the physical components of a computer ] that is often part of an ICT system.

This is why your GCSE is not just about computers but about how, why and when people use them. It is the power of computers and communications that has allowed ICT systems to become so important. Like any piece of equipment, the important thing about it is what it lets us do.

ICT Systems are used in a number of environments, such as:

  • offices
  • shops
  • factories
  • aircraft
  • ships

They're also used in fields such as:

  • communications
  • medicine
  • farming

ICT Systems are everyday and ordinary, yet extraordinary in how they can add extra power to what we do and want to do.

The importance of ICT systems

By using ICT systems we are:

  • more productive - we can complete a greater number of tasks in the same time at reduced cost by using computers than we could prior to their invention
  • able to deal with vast amounts of information [information: data with context or meaning ] and process it quickly
  • able to transmit and receive information rapidly

Types of ICT system

The three main types of ICT system to be considered for GCSE are:

Information systems

This type of ICT system is focused on managing data [data: information without context, eg a list of students with numbers beside their names is data, when it's made clear that those numbers represent their placing in a 100 metre race, the data becomes information ] and information [information: data with context or meaning ]. Examples of these are a sports club membership system or a supermarket stock system.

Control systems

These ICT systems mainly control machines. They use input [input: Everything that goes into a system. The three most common inputs in industry are physical inputs, labour and capital. ], process and output [output: the term denoting either an exit or changes which exit a system and which activate/modify a process ], but the output may be moving a robot arm to weld a car chassis rather than information.

Communications systems

The output of these ICT systems is the successful transport of data from one place to another.

Input, output and system diagrams

What comes out of an ICT system is largely dependant on what you put into the system to begin with.

ICT systems work by taking inputs (instructions and data [data: information without context, eg a list of students with numbers beside their names is data, when it's made clear that those numbers represent their placing in a 100 metre race, the data becomes information ]), processing them and producing outputs that are stored or communicated in some way. The higher the quality and better thought-out the inputs, the more useful the outputs.

Garbage In, Garbage Out (GIGO)

ICT systems cannot function properly if the inputs are inaccurate or faulty; they will either not be able to process the data at all, or will output data which is erroneous or useless.

GIGO is a useful term to remember in the exam - it can help explain many issues such as why validation is needed and why accurate data is valuable.

GIGO stands for Garbage In, Garbage Out

An ICT system diagram

A system is an assembly of parts that together make a whole. ICT systems are made up of some or all of the parts shown in the diagram. Various devices are used for input, processing, output, and communication.

Shows how people (users, clients, customers, operators, technicians, governments, companies) use ICT systems for storage (temporary memory - RAM, hard disks, magnetic tapes. Input (where data is collected or captured) leads to processing (working with information, changing , calculating, manipulating), which is then output (showing results on the screen, printouts, email) and can be communicated (sending results, collecting data, feedback).

ICT systems can be made of some or all of the parts shown.

Feedback

It is sometimes good to have feedback in an ICT system. This is when the output [output: the term denoting either an exit or changes which exit a system and which activate/modify a process ] from a system feeds back to influence the input [input: Everything that goes into a system. The three most common inputs in industry are physical inputs, labour and capital. ] and the process repeats itself.

A good example is a system set-up to control water temperature in a tropical fish tank. The temperature of the water is taken as an input from sensors [sensor: an automatic input device that continuously monitors a set of computer controlled parameters, eg a parking sensor detects how close a vehicle is to the nearest object and alerts the driver if the distance falls outside of the specified parameters ]. Processing takes place and the temperature of the water is compared against the pre-programmed parameters, eg maximum/minimum temperature. The outputs include the automatic decision to either turn on or off the heater to warm or let the water cool. The output, ie the change in the water's temperature, is then fed back by the sensors as an input and the process repeats itself.

Flowchart shows how the sensor dects the rise in temperature. The processor then compares this reading with the temperature rule. The water heater is turned off. The water temperature falls. The sensor detects a drop in the temperature. The processor compares this reading with the temperature rule. The water heater is turned on. The water termperature rises, causing the sensor to detect the change and the process to begin again.

A system that monitors the water temperature of a fishtank and reacts accordingly.

Feedback can occur in information [information: data with context or meaning ]-based systems as well. Often an output will have a result on further inputs. For example, the output of accepting an online booking for an air ticket will be to reduce the number of tickets available.

The Measurement and control section has more information about the feedback cycle.

Media integration

Methods used for input [input: Everything that goes into a system. The three most common inputs in industry are physical inputs, labour and capital. ] to and output [output: the term denoting either an exit or changes which exit a system and which activate/modify a process ] from ICT systems vary a lot. In your revision you need to be familiar with examples of input and output formats.

Input and output formats are the different kinds of media [media: The plural form of medium - examples include paint, clay, glass, textiles, photography, print and so on. Wet media includes paints and pens. Dry media includes pencils and charcoals. ] that are used to either gather up and collect data [data: information without context, eg a list of students with numbers beside their names is data, when it's made clear that those numbers represent their placing in a 100 metre race, the data becomes information ] and instructions or to display, present or issue the outputs of processing.

Up until recently most media formats required dedicated devices - for example, digital cameras to take digital [digital: data measured at discrete intervals, eg a digital watch typically moves from displaying one second to the next without displaying the values in-between ] photographs, scanners to digitise images for use on a computer, or DVD [Digital Versatile Disc (DVD): used to store data, eg a movie ] players for video playback - so you needed the correct device in order to work with each media format.

Touchscreen mobile phone with browser display GCSE Bitesize website

There is now a growing tendency for multi-purpose ICT devices or conversion. The driving force is the communication power of the Internet [Internet: a global network connecting millions of computers ], and the increasing availability of small high-powered electronic technology. This means that you can now get an all-in-one box that can do the same thing as several different ones did before it. Here are some examples:

  • combined printers, scanners and photocopiers
  • televisions with built-in Internet connections [Internet connection: a computer's or another internet-enabled device's connection to the Internet ] and web browsers [web browser: an application used to browse the Internet or view web pages ]
  • mobile phones that can take photos, record video, access the Internet and play back music

Find out more about the power of the Internet in the Networks and communications section.

Integration of information services

Alongside the joining together of technologies, there is also a tendency toward the integration of common public information services.

iPlayer homepage showing TV and radio highlights

Digital [digital: data measured at discrete intervals, eg a digital watch typically moves from displaying one second to the next without displaying the values in-between ] television by satellite, cable [cable: a data communications technology that provides broadband Internet speeds over the cable television infrastructure ] or terrestrial aerial now gives access to many channels that have interactive content, which can be used in a similar way to the web. DAB digital radio provides large amounts of text data [data: information without context, eg a list of students with numbers beside their names is data, when it's made clear that those numbers represent their placing in a 100 metre race, the data becomes information ] to be transmitted along with the signal. The Internet [Internet: a global network connecting millions of computers ] now enables broadcasts from radio and TV stations to be 'time-shifted' by the user, who watches or listens to the programme whenever they want to.

News services and the mass media such as newspapers, radio, and television are making themselves available so that people can access them when they want and wherever they are. Two of the key reasons for this are:

  1. The growth of broadband [broadband: high speed Internet access ] Internet access that allows lots of information to be viewed quickly and effectively.
  2. The success of digital broadcasting [digital broadcasting: Soon to replace analogue broadcasting in this country altogether. A greater number of channels can be offered as well as interactive services, eg the red button. ], the signals of which can carry very much more content than old style analogue [analogue: continuous data, eg the second hand on an analogue watch displays each second and the space in-between ] TV and radio.

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