The Difference between a Computer and a Computer System
A Computer is an electronic and programmable machine that accepts and takes in digital data, which are automatically processed before being output in some way.Â It is programmable, so that the rules used to process the data can be changed. Therefore, a computer is an automatic, programmable, digital data processor.
A Computer System is the complete collection of components (hardware, software, peripherals, power supply, and communication links) making up a single computer installation. The particular choice of components is known as the configuration â€“ different systems may or may not have the same configuration.
Hardware and Software
There are two parts to all computer systems, namely the hardware and the software.
Hardware is the physical part of a computer system â€“ the processor(s), storage, input and output peripherals. Therefore, hardware is the term used for the parts of the computer that you can see, touch and handle. Hardware is the collective name given to all the devices that make up a computer system.
Some examples of hardware that make up a computer system include, a Visual Display Unit (VDU) that is the screen, the speakers, the keyboard, the mouse, the microphone, the Central Processing Unit (CPU) or the System Unit.
Basically, the hardware devices may be:
- Input Devices: Used to get the data into the computer.
- Central Processing Unit (CPU): The brain of the computer.
- Backing Storage: Consists of the disk drives used to store data when the power is switched off.
- Output Devices: Include such units as the printers and VDUs, which are used to provide output in the form of printouts and screen displays.
Figure 1 below shows an example of all the components (hardware devices) that make up a computer system.
Figure 2 displays the arrangement of the components in a typical computer system.
Software consists of programs, routines and procedure (together with their associated documentation) that can be run on a computer system. So, software is the word used for the actual programs that allow the 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 CD Burner and a blank CD. The CD Burner and the CD are the â€˜hardwareâ€™ because we can actually pick them up. But if we burn some music on the CD, then the music would be the â€˜softwareâ€™.
How Computer normally functions:
This describes the fact that a computer takes in digital data, which is processed in some way, before being output as a piece of information.
Raw facts and figures are called Data. Facts and figures have little meaning until they are sorted or until we calculate something from them. This sorting or calculation is called Data Processing.
So, data are information coded and structured for subsequent processing, generally by a computer system. The resulting codes are meaningless until they are placed in the correct context. The subtle difference between data and information is that information is in context and data are not.
Information is the result of data processing. So information is the meaning we attach to the data. For instance, a red traffic light is a form of data. The meaning we attach to this data (that is STOP) is the information. Sometimes, data can give rise to ambiguous information. If you are driving a car and a car is travelling in the opposite direction flashes its lights at you, what does it mean? It could just mean that a friend has spotted you and is saying hello; it could also mean that there is an accident further up the road. The information that may be obtained from data depends on the way the data is interpreted and the context in which it is used.
Advantages of Using Computers
- 1. Computers enable tele-working.
Computers enable employees to work from, which is a facility for them, in the sense that they can work at their own pace. For example, the employees can start working at any time they want to. This is because, they will not have the rush to go to work, as there are some employees who have to drop their children at school before going to work, which eventually lead to late arrivals at work in most cases.
Hence when working from home, this enable the employees to start working at the time that is convenient for them, provided that they work the amount required per day. For instance, an employee has to work 8 hours per day and in this way whatever the time an employee starts to work he should work for 8 hours a day.
- 2. Computers are helpful in education.
Computers provide students with useful tools which prove to be beneficial and useful in their education. For example, there is the Microsoft Office, which consists of Microsoft Word to help them to prepare for their assignments and project; Microsoft Excel to prepare for statistical projects.
Additionally, nowadays with latest technologies, the students can have access to the internet anywhere with their laptops. They can access the internet anywhere by means of WiFi. And on the internet the students can do researches about a particular topic in order to increase their knowledge or to look up for information for a project.
- 3. Computers can be used as a means of communication.
Computers can avoid a person from moving from one place to another, as from one place we can easily communicate with another person. This means that a message can easily be sent to another person from a computer or a laptop. For example, an email can be sent to another person, without the need to go to the post office to post a letter. Furthermore, files can be attached in the mail.
Social Networking, like Facebook, can also be accessed from your Personal Computer or laptop, where you can keep in touch with friends or relatives who live anywhere in the world.
- 4. Computers can store large amount of data.
Compared with a filing cabinet (which is a manual system), a microcomputer is able to save a large amount of data, where many filing cabinets may be required to save the same amount of data that the computer can hold on his disk. In this way, storing data on a computer will also help to save physical space in an office.
- 5. Computers can work 24 hours a day.
Computers do not fall ill or they do not take lunch breaks or tea breaks and they do not go on strikes. So, computers can work 24 hours a day and 365 days a year without tiring and without complaining. There are some tasks which are better left to humans though.
- 6. Computers are very accurate.
Computers are able to provide accurate information, provided that the data being fed to the computer are correct. If the data input to the computer are incorrect, then the computer will produce and output strange answers, as they will not realize that these data are wrong. However, if the computer is given the correct and right information, then provided the hardware and software are working correctly, the computer will always produce the right output.
This whole concept is termed as GIGO, short for â€œGarbage In Garbage Outâ€.
- 7. Computers can do some jobs which would be impossible without them.
Airline booking, the use of credit cards, Switch cards, weather forecasting and space exploration would all be much difficult without computers.
Disadvantages of Using Computers
- a. Computers can lead to unemployment.
There are some jobs that can be done by computers and therefore, there is no need for persons to carry out these tasks. Thus there is no doubt that the use of computers has lead to unemployment.
- b. It becomes frustrating when computers become unusable.
There are some works which require the use of computers. So when the computers become unusable, the works remain pending and it is frustrating for the workers. For example, if the cash tills at a supermarket are not working, then sales cannot be carried out, or if computers in an air travel company has broken down, then booking will not be done. Another example can include the breakdown of ATMs or the computers within the banks which will not allow the use of bank cards.
- c. The loss of privacy due to computers.
Computers can also be used to hack the personal details of individuals. Computers can be used to hack all the personal data stored on a database, for example a hacker can hack the personal information of the staff of a particular organization. Even on the social networking, like Facebook, illegal access to the personal information of persons can be possible.Â In this way, once the personal data have been hacked, they can be used in the wrong way, like to blackmail someone for any personal reasons.
- d. Computers can lead to health problems.
There are many health problems that can arise when using and working with computers for long periods of time. Repetitive Strain Injury (RSI), backaches, eyestrains, headaches and skin rashes are conditions which can occur. Computers also lead to techno stress and also to other health problems that you didnâ€™t have.
The Central Processing Unit â€“ CPU
The Central Processing Unit, often called the CPU or simply the processing unit, is the main part of the computer, consisting of registers (memories), Arithmetic Logic Unit (ALU) and the Control Unit (CU).
The Central Processing Unit processes raw data and turns it into information. A special form of the Central Processing Unit is the microprocessor, which is used in the microcomputers and small computerized devices, like the washing machines. The microprocessor normally consists of a series of circuit boards containing the main processor along with various memory chips.
You will find a transformer and sometimes a fan that is often responsible for the hum that you get from a computer. Chips give out quite a bit of heat during operations, so fan is used to cool them down.
The Central Processing Unit consists of three main elements, namely:
- Control Unit â€“ CU: Is the part of the central processor that manages the execution of instructions. A characteristic of all computers is the ability to follow a set of instructions automatically. The control unit fetches each instruction in sequence, and decodes and synchronizes it before executing it by sending control signals o other parts of the computer. Therefore, the control unit is responsible for the input devices and output devices.
- Arithmetic and Logic Unit â€“ ALU: Is the part of the central processing unit where data are processed and manipulated. The processing and manipulation of data normally consists of arithmetic operations or logical comparisons allowing a program to take decisions. So the arithmetic and logic unit is where all the calculations and logical decisions are made.
- Immediate Access Store â€“ IAS: Provides immediate memory for holding data and programs. The IAS is on a chip or a series of chips inside the computer. Data held can be accessed immediately, unlike data held on disk, which can take some time to load.