The Components of an Information System

The Components of an information System

Hardware and software

There are two parts to all computer systems: the hardware and the software. Hardware is the term used for the parts of the computer that you can touch and handle. Hardware is the collective name given to all the devices that make up a computer system. Some examples of computer hardware are shown in Figure 2.1. Basically these devices may be split into:

·       Input devices. Which are used to get the data into the computer

·       The central processing unit, which is the brain of the computer

·       The backing storage which consists of the disk drives used to store data when the power is switched off

·       The output devices, which include such units as printers and VDUS, which are used to provide output in the form of printouts, screen displays, etc.

The part of a typical microcomputer

 A simple computer system

 The arrangement of these in a typical computer system is shown in Figure 2.2 above.

          Software is the word used for the actual programs that allow the hardware to do a useful job. Without software, hardware to do a useful job. Without software, hardware is useless. Software is made up of a series of instructions that tell the computer what to do.

          To understand the difference between hardware and software, think of a tape recorder and a blank tape. The tape recorder and the tape are the ‘hardware’ because we can actually pick them up. But if we recorded some music onto the tape, then the music would be the ‘software’.

Why use Computers?

Computers and extremely fast

A large computer used for producing weather forecasts is able to perform over one million calculations per second. This may appear to be excessive, but many millions of calculations are needed to produce a weather forecast, and forecasts need to be produced quickly.

          Computer systems used by the gas and electricity companies have to produce bills to be sent out every three month. Without fast and powerful computers this would be impossible.

Computers are very accurate

We have to remember when we see stories in newspapers about computers making huge mistakes that it is the people who have programmed them or entered the data that have made the mistakes. Computers only do what they are told to  do. We often use the saying garbage in, garbage out’ (GIGO for short): what it means is that if incorrect data is put into a computer, the computer won’t realize into a computer, the computer won’t realize that it is incorrect so it will produce a strange answer. If the computer is given the right information, then provided the hardware and software are working correctly, it will always produce the right output.

Computers can keep large amounts of information in a small space

Keeping all the information we need written on paper in files is an enormous task. Once you have gone through the tedious task of making up the files and cataloging them, there is the problem of finding the file you want; sometimes you may have millions of them to hunt through! But if you use computerized storage you can keep millions of files a very small space and get the information from them in second. You can also have a spare copy in case of accidents – imagine having duplicate written files.

Computer can work continuously for 24 hours a day

Computers don’t become ill, they don’t take lunch breaks or tea breaks and they don’t go on strike. Computers can easily work 24 hours per day. 365 days per year. There are many things that are probably best left to humans though.

Computers can do some jobs that would be impossible without them

Airline booking, the use of credit cards and Switch cards, weather forecasting and space exploration would all be much more difficult without computers.

 

Many things are best left to humans

To be continued…..