Information and Communication Technology
The term ICT system covers a wide range of different types of equipment, which may be connected together in an equally wide range of ways.
Fortunately, as far as the IGCSE is concerned, an ICT system is defined in a much narrower way. You need only consider simple systems, consisting of a main computer or a device containing a microprocessor , plus peripherals such as keyboards, mice, monitors, etc.
The term Information and communications technology (ICT) is a relative latecomer. It wasn't really used much before 2000, when the UK government started using it in the National Curriculum.
ICT is an extension of the term Information technology (IT), which refers to the use of computers and related hardware in acquiring, processing, storing and distributing electronic data. The communications bit was added in to reflect the increasing role of electronic communications via computer systems.
An information system (IS) is a further extension. Information systems consist of IT / ICT and human activities. The term is frequently used to describe systems involving hardware, data, processing, etc. which are used to support businesses and other organisations.
The term ICT system includes a wide variety of devices. PCs and laptops may be the ones you think of first, but there are many other types as well. These include:
Personal Computers, PCs, are general purpose machines. They are designed for individual use rather than being shared systems like mainframes.
Laptops are really just PCs that have been made smaller and more portable. Originally they were ones that could be carried around but still had to be plugged into mains power to run. Nowadays they can run on batteries.
They were originally known as micro-
Nowadays, the term PC may be used to describe desktop machines, laptops, tablet PCs, palmtops and other handheld devices.
The Colossus computer shown in the introduction is a Supercomputer. That means it was built to do calculations as fast as possible, with all its resources being used for one task at a time, in this case code breaking.
When it took part in a code breaking challenge in 2007, it was easily beaten by a 1.4GHz laptop. The winner, Joachim Schueth , said; "My laptop digested ciphertext at a speed of 1.2 million characters per second -
But does that mean that a 1.4GHz laptop is a Supercomputer? Obviously not. The point is, the terms Mini, Mainframe and Supercomputer really refer to the job being done, not the power of the machine doing it.
A Supercomputer is build for speed of calculation, they are usually custom made and designed for a specific purpose. e.g. a machine called Deep Blue was created to play Chess.
More typical uses include weather forecasting and aircraft design.
Mainframe computers have as much processing power as a Supercomputer, but instead of concentrating on speed for a single purpose, they are designed to be able to carry out numerous tasks at the same time. They can run hundreds of Virtual Machines, each working on a different task.
A typical user would be a large company or other major organisation such as a hospital.
Mini computers were originally machines that were built as mini-
So, in summary, the terms mini, main and super don't tell you what they are, they tell you what they do.
Embedded computers are so named because they are generally found as part of, embedded in, another device.
They tend to have a limited number of functions, or even just one and often use custom built operating systems and software.
Some embedded systems must have exceptional reliability
and robustness. This may be because of the problems
caused if it goes wrong e.g. in vehicle braking or aircraft
control systems. It may also be because of where the
system is, e.g. on a satellite or at the bottom of the sea.
A great deal of money and effort goes into ensuring that
this sort of system will not go wrong.
Other embedded systems are designed to keep costs to a
minimum and are often 'just good enough'. This sort of
system may be found in e.g. mobile phones or digital cameras.
Computer use is becoming more common every day.
Computers are taking over tasks that used to be purely
mechanical. e.g. controlling car engines, regulating oven
They are being put into simple devices to give them more
functions. e.g. mobile phones used to just make phone
calls, now they take photos, or video, let you connect to
a friend's phone to play games, and allow you to browse
You can find computers in schools, offices and factories,
they provide entertainment and allow you to communicate
around the world, they control the traffic and predict the
weather. And they're getting cheaper and easier to use.
In fact, there are very few electronic devices remaining in the home that do not have at least some simple embedded computer in them. TV's, TV remotes, printers, Digital TV Boxes, washing machines, cookers etc. The computers that are truly ubiquitous are probably the ones that people least notice. Many of these may actually be based on general purpose computing elements with specific programs -
So the answer to who uses a computer and where? Is most of the world and most of the world.