Introduction to Computer
Introduction to Computer
We are living in the age of computers. Most of our daily activities are being influenced by the use of computers. IT and computers have become an integral part of our lives.
A computer is an automatic electronic machine that converts raw data into useful information with the help of certain instructions. These instructions are issued in form of a program (a set of instructions is called a program).
A program is a sequence of instructions, written in a specific computer language, which operates on data to perform a certain task.(or) A computer program is a collection of instructions that can be executed by a computer to perform a specific task. A computer program is usually written by a computer programmer in a programming language.
Input process output model
Computer input is called data and the output obtained after processing it, based on the user's instructions is called information. Raw facts and figures which can be processed using arithmetic and logical operations to obtain information are called data.
The processes that can be applied to data are two types-
Arithmetic operations - Example include calculation like addition, subtraction, differentials , square root etc.
Logical Operations - Examples include comparison operations like greater than, less than, equal to , opposite, etc.
The corresponding figure of an actual computer looks somethings like this -
I-P-O CYCLE
This is termed as Input Processing Output (IPU) Cycle. A computer receives data as input processes, stores it and then produces output.
The working of a computer is shown in the following figure:
It functions in the following manner:
Input : computer input is whatever is entered or fed into a computer system. Input can be supplied by a person (such as by using a keyboard) or by another computer or device ( such as a diskette or CD - ROM ). Some examples of input include the words and symbols in a document, numbers for a calculation, instruction for completing a process, pictures, and so on.
(or)
Devices like keyboard and mouse that are used to input data and instructions to the computer are called input unit.Processing- The computer performs useful operations by controlling the data in many ways. This work is called processing. Examples of processing include performing calculations, sorting lists of words or numbers, modifying documents and pictures according to user instructions, and drawing graphs. A computer processes data in the CPU.
Storing- The computer stores data. A computer must store data
So that it is available for processing. Most computers have more than one location for storing data ( the hard drive or C:\, and the floppy drive or A:\).
The computer puts the data in one place while it is waiting to be processed and another place when it is not needed for immediate processing.
Output- the computer produces output. Computer output is information that has been generated by a computer. Some examples of computer output include reports, documents , music, graphs, and pictures. Output can be in several different formats, such as paper, diskette, or on screen.
Arithmetic Logic Unit- This is the brain of the computer where all arithmetic operations and logical operations take place.
Memory- All input data, instructions and data interim to the processes are stored in the memory. Memory is of two types – primary memory and secondary memory. Primary memory resides within the CPU whereas secondary memory is external to it.
Components of Computer
Computers are made up of two parts: the hardware, the software. The physical equipment required to create , use, manipulate and store electronic data is referred to as hardware. The computerised instructions that operate a computer manipulate the data and execute particular functions or tasks are referred to as software.
All Computers require the following hardware components :
Central Processing Unit ( CPU)
This is also known as the brain of a computer. This is a single chip (sometimes more than one chip) located at the heart of a computer that enables it to process data. Also known as a processor.
CPU
Memory
This is an area within a computer system that holds data waiting to be processed.
RAM Storage Device
This is the place where a computer puts the data for future references ( like as Hard Disk).
Note : Operating System is installed and stored on the hard disk.
Hard Disk Input Devices
The devices that allow data and instructions to be entered in a computer ( such as keyboard, mouse scanner).Output Devices
The devices that allow information to be represented (i.e., given out) to the user, such as a display screen or printer).
Benefits of a Computer
There are many benefits of using a computer. Some of them are given as under.
Accuracy:
If the input of instructions given to a computer is correct, there is no scope for errors in the tasks performed by a computer.
Fast Speed:
A Computer works at great speed. The Computer can perform complex tasks within no time. It can process the data and information in a blink of an eye which otherwise may take months together.
(C) Diligence:
When human beings do a job again and again, they get fed up with a monotonous
job and lose their concentration. But computers have absolute diligence in working. It can work tirelessly for hours together with the same speed and accuracy.
(D) Versatiltiy:
Computers can perform multiple tasks of different nature at one and the same time. One can write an article in MS Word on a computer taking assistance from a computer dictionary while listening to online music of one’s choice at the same computer and can take printouts of some documents simultaneously.
(E) Storage
Computers have the ability to store large amounts of data. One can store hundreds
Of books on one DVD which otherwise may occupy one room for storage. Further,the
Required information can be accessed even after several years with 100% completion and accuracy.
(F) Automation
A computer can automatically perform operations freeing the user during such
Operations. It controls automatically different devices attached with the computer. It
Executes automatically the program instruction one by one.
(G) Reliability
The electronic components in modern computers have very low failure rate. A
modern computer can perform very complicated calculations without creating any
Problem and produces consistent ( reliable) results. In other words, when a computer
Is 100% accurate, then its reliability is also 100%.
(H) No Feelings
Computer is an electronic machine. It has no feelings. It detects objects on the basis of instruction given to is. Based on our feelings, taste, knowledge and experience: we can make certain decisions and judgments in our daily life. On the other hand, a computer can not make such judgments on their own. Their judgments are totally Based on instructions given to them.
Classification of Computer
Computers are classified according to their data processing speed, amount of data that they can hold and process. Depending upon their speed and memory size, computers are classified into the following four main groups.
Analog Computer - Analog Computers are used mostly in Medical Sciences. This very kind of computer work on continuous data values , for e.g. if you have to calculate the pressure or something similar then kind of technology having will be useful. if i talk about in the simple way then -An analog computer (spelt analogue in British English) is a form of computer that uses continuous physical phenomena such as electrical, mechanical, or hydraulic quantities to model the problem being solved.
Micro Computer- These computers are also called personal computers. Two major types of these computers are laptop or desktop computers. Only one user uses these computers at a time that’s why they are also known as personal computers.
The personal computer is mostly preferred as home computers, and almost all users are familiar with them. The memory size and working capabilities of these computers are quite low in comparison to other classes of computers.
These computers use a microprocessor chip ( MPU ) and this chip is used instead of a CPU which means that this microprocessor chip works as a CPU.
(or)
In the simple language : The processor is very small so that called Microprocessor and device is called a micro computer . Micro Computer is a single user device example: Desktop , Laptop ,Palmtop ,Notebook , PDA etc.
There are various types of computers as discussed below.
(a) Desktop computer - A desktop Computer is a personal computer (PC) in a form intended for regular use at a single location. These are generally kept on a table top to work upon. This type of computer is also known as the name of a digital computer.
These are the most common types of micro computers.
Two popular series of personal computers are the IBM PC and the Apple
Macintosh.
(b) Notebook Computer / Laptop Computer - A notebook computer is also called a laptop. A notebook computer has the processor, memory, keyboard, computer hard drive and the display integrated into a single unit that can operate on battery. A notebook is a small, lightweight computer that you can easily transport from one place to another. Users with mobile computing needs, such as business travellers, often use a laptop.
(c) Tablet PC- A Tablet PC is a wireless, portable personal computer with a touch screen interface. The tablet form factor is typically smaller than a notebook computer but larger than a smartphone.
The tablet PC relies on digital ink technology, where a digitizer is laid under or over an LCD screen to create an electromagnetic field that can capture the movement of the special purpose pen and record the movement on the LCD screen. The effect is like writing on paper with liquid ink.
(D) Personal Digital Assistant (PDA)- PDAs are handheld devices that were originally designed as personal organizers, but became much more versatile over the years. PDAs have many uses: calculating, use as a clock and calendar, playing computer games, accessing the internet, sending and receiving e-mail, and use as a video recorder, recording notes, use as an address book and use as a spreadsheet.
Newer PDAs also have both colour screens and audio capabilities, enabling them to be used as mobile phones, web browsers or portable media players. One of the most significant PDA characteristics is the presence of a touch screen.
 |
| PDA |
Mini Computer - Mini computers are computers that are somewhere in between a micro computer and a mainframe computer. A mini computer is a multi-user system. They are used to control machines in a manufacturing unit. They have higher memory, higher processing power and higher storage as compared to micro computers.
Mini Computer Mainframe Computer - mainframe computers can process several million-program instructions per second.mainframe computer have more storage capacity Large organizations rely on these room-size systems to handle large programs with lots of data. Mainframe are mainly used by insurance companies, banks, airlines, and railway reservation systems, etc.
Mainframe Computer Super computer - super computers are the fastest calculating / high speed device ever invented. The largest in size, the most expensive than any other is assessed and known as a super computer.
It processes trillions of instruction in seconds. These machines are for applications requiring very large programs and huge amounts of data / large numbers of data that must be processed quickly.
Governments specially use a super computer for their totally different calculations and significant jobs. Moreover, different industries use this huge computer for designing their products.
In most of the Hollywood's movies it’s used for animation purposes. This type of computer is additionally useful for forecasting weather reports worldwide.
 |
| Super Computer |
Comments
Post a Comment