Date : 12/24/2018, 12/25/2018, 12/27/2018
Introduction to Computers
What Is A Computer?
A computer is a general purpose device which can be programmed to carry out a finite set of arithmetic or logical operations. Since a sequence of operations can be readily changed, the computer can solve more than one kind of problem. - Wikipedia
A computer is, at its most basic, a machine which can take instructions, and perform computations based on those instructions. - wiseGEEK
A computer is an electronic device which is capable of receiving the inputs (data from the user), storing it for a desired period of time, manipulating it according to the set of instructions (called program) and producing the output to the user in desired form. It performs a variety of operations in accordance to the set of instructions. - //www.trivology.com
A computer is an electronic device that manipulates information, or "data". It has the ability to store, retrieve, and process data. You can use a computer to type documents, send email, and browse the internet. You can also use it to handle spreadsheets, accounting, database management, presentations, games, and more.
When reading the above definitions you may find some common behaviors of computers such as;
- It is a man-made machine
- It accepts instructions of a human given in a sequential manner
- As per the given instructions, it performs some calculations and does changes for the information fed by human
- Releases or produces an output that is useful to the user
Devices that comprise a computer system
What Does A Computer Do?
Computers can perform four general operations, which comprise the information processing cycle.
- Input
- Process
- Output
- Storage
Data and Information
All computer processing requires data, which is a collection of raw facts, figures and symbols, such as numbers, words, images, video and sound, given to the computer during the input phase.
Computers manipulate data to create information. Information is data that is organized, meaningful, and useful. During the output Phase, the information that has been created is put into some form, such as a printed report.
The information can also be put in computer storage for future use.
How Does a Computer Know what to do?
- It must be given a detailed list of instructions, called a compute program or software, that tells it exactly what to do.
- Before processing a specific job, the computer program corresponding to that job must be stored in memory.
- Once the program is stored in memory the compute can start the operation by executing the program instructions one after the other.
What Are The Primary Components of a Computer ?
- Input devices.
- Central Processing Unit (containing the control unit and the arithmetic/logic unit).
- Memory.
- Output devices.
- Storage devices.
Why Is A Computer So Powerful?
- Speed
- A computer can perform tasks very fast. For example, the amount of work that a human being can do in an entire year (if he worked day and night and did nothing else) can be accomplished by a computer within a few minutes. As you are aware now, inside the system unit, the operations occur through electronic circuits. When data, instructions, and information flow along these circuits, they travel at close to the speed of light. This allows billions of operations to be carried out in a single second.
- Reliability
- Electronic components in modern computers are dependable because they have a low failure rate. The high reliability of the components enables the computer to produce consistent results.
- Accuracy
- The accuracy of a computer is consistently high and the degree of accuracy of a particular computer depends upon its design. Errors can occur in a computer, but these are mainly due to human mistakes. Thus, computers can process large amounts of data and generate error-free results, provided the data is entered correctly. If inaccurate data is entered, the resulting outputs will also be incorrect. This computing principle is known as Garbage in, garbage out (GIGO).
- Diligence
- Unlike human beings, a computer is free from boredom, tiredness, lack of concentration, etc., hence a computer can work for hours without making any errors or complaints. Even if ten million calculations have to be performed, a computer will perform the ten millionth calculations with exactly the same accuracy and speed as the first one.
- Versatility
- The computers have the capacity to perform completely different type of work. You may use your computer to prepare payroll slips at the moment. Next moment you may use it for inventory management or to prepare electric bills. The computers are flexible enough to adapt to any type of work and outputs according to what is fed and instructed.
- Power of remembering
- Computer gives any information when it is needed and can be recalled when necessary. even after several years.
- No Feeling
- Computers do not have emotions. They have no feelings and no instincts because they are machines. Although human beings have succeeded in building a memory for the computer, a computer does not possess the equivalent of a human brain. Based on our feelings, taste, knowledge and experience, we often make certain judgments in our day-to-day life, but computers cannot make such judgments on their own. Their judgment is based on the instructions given to them in the form of programs by someone.
- No IQ
- Computer is a dumb machine and it cannot do any work without instruction from the user. It performs the instructions at wonderful speed and with accuracy. It is you to decide what you want to do and in what sequence. So a computer cannot take its own decision as you can.
- Storage
- The computer has an in-built memory where it can store a large amount of data. This is called Primary Storage. This Primary Storage has a limited capacity but it is very important as the processing unit of the computer can act directly only on instructions and data on the primary storage. But, you can also store data in secondary storage devices such as floppies, which can be kept outside your computer and can be carried to other computers. These are called Secondary Storage. Before the computer can process the data stored in Secondary storage devices, the data must be moved from secondary storage device to primary storage. This is not a serious drawback. The computers can retrieve information from files in a secondary storage device in a few milliseconds.
Limitations of a Computer
It is obvious that the computer has a variety of capabilities. Similarly, this man made machine has some its own limitations as well. Such limitations are given below:
- The computer can do only what you tell it to do-you cannot expect the computer give you something which you did not ask.
- It cannot generate information on its own-the computer will work only if you operate it and give the instructions. It cannot give you information unless you feed it required data.
- It will give wrong information if you feed it with wrong data- the computer cannot identify what the correct data and what the wrong data are.
- It cannot correct wrong instruction- if you give the computer wrong instruction, it will not be able to do anything to rectify it. The only thing it can do is to stop functioning till you correct the mistake.
Uses of Computer
Office Applications
Stock Control
Stock control is ideal for automation and in many companies it is now completely computerized. The stock control system keeps track of the number of items in stock and can automatically order replacement items when required.
Accounts / Payroll
In most large organizations the accounts are maintained by a computerized system. Due to the repetitive nature of accounts a computer system is ideally suited to this task and accuracy is guaranteed.
Automated Production Systems
Many car factories are almost completely automated and the cars are assembled by computer-controlled robots. This automation is becoming increasingly common throughout industry.
Design Systems
Many products are designed using CAD (Computer Aided Design) programs to produce exact specifications and detailed drawings on the computer before producing models of new products.
Computers in Daily Life
- Accounts
- Games
- Educational
- On-line banking
- Smart ID cards
- Supermarkets
- Working from home (Tele-working)
- Internet