Computer is a modern device that is used to take data from the user to apply its different algorithms and generate output for the given data.
Computer is a modern device that calculates the result for given data using a combination of different hardware and software.
the Computer derived from the Latin word “computer” which means “calculate” basically computer is a device which takes data from the user in different shapes and then applies its different kind of algorithms to generate a result for accepted data. Computers system whenever takes data from the user each time it passes accepted data from different phases from input to result. Generally, these phases can be categorized into three parts. Each phase has its own characteristics and functionality.
Whenever data passes from any of the three stages shapes of the data converts from one shape to another. As the human-computer system also has its own language which can directly understandable for the computer system. The computer system language is binary language. In other words, we can say the computer operates and understand instructions in binary bits.
Any instruction is given to the computer system it will accept given instructions but computers can not understand it before generate the result and execution first of all computer system will convert this instruction into its own language after conversion computer system will apply its different type of functions and algorithm to generate the result of the instruction.
Here one question arises that why for an electronic computer system binary language is understandable?
The answer to this question is very simple due to the internal structure of these computer systems its language is binary. An electronic computer system is made up of ICs (Integrated circuits ) while these ICs are the combination of logical gates are seven in numbers and each of which operates on Boolean values or binary digits this main point generates the main evidence of the binary language direct understanding of the computer system.
A computer system has a relation with more than one field of life. In other words, we can say that the computer system has a relationship with each and every field of life we can not say that the computer has a relation with only one field.in general terms, we have only one idea that computer system has relation only with electronic field due to its definition but when we further express its types and working then we can get the answer that computer system has relation not only with the electronic field but also has a great part in the electrical mechanical chemical, etc field.
A computer system has its own machine language but this language only runs on that hardware machine language of one hardware can not run on the other hardware its code has some short of changes that are not understandable for the other hardware.
Characteristic of the computer system:
Man developed a computer so that it could perform intricate operations such as calculation and data processing or entertain him. Today computers are everywhere in our offices homes appliances and automobiles the list is endless much of the world’s infrastructure runs on computer and the computers have profoundly changed our lives mostly for the better let us discuss some of the characteristics of a computer which make it an essential part of every emerging technology and such a desirable tool in human development. Few characteristics of the computer system are given as under:
The computer process data at an extremely fast rate i.e at millions or billions of instructions per second in a few seconds a computer can perform a huge task that a normal human being may take days or even years to complete the speed of a computer is measured in megahertz(MHz)that is one million instructions per second.
Besides being efficient the computers are also very accurate the level of accuracy depends on the instructions and the type of machines being used since we know that the computer is capable of doing only what it is instructed to do faulty instructions for processing the data automatically lead to faulty results the faulty results due to faulty instructions or incorrect input data are known as GIGO that is garbage in garbage out.
Generally, reliability is the measurement of the performance of a computer which is measured against some predetermined standard for operation without any failure the major reason behind the reliability of the computers is that at hardware level it does not require any human intervention between its processing operations moreover computer have built-in diagnostic capabilities which help in continuous monitoring of the system.
Computers can store large amounts of data and it can recall the required information almost instantaneously the memory of the computers is relatively small and it can hold only a certain amount of information, therefore, the data are stored on storage devices such as magnetic tape or disks the data from these devices can be accessed brought into the main memory of the computer as and when required for processing.
A computer is quite versatile in nature they can perform multiple tasks simultaneously with equal ease for example at one moment it can be used to prepare a letter at the other moment it can be used to play music and in between, one can print a document as well all this work is possible by changing the program.
A computer being a machine does not suffer from the human train of tiredness and lack of concentration if four million calculations have to be performed then the computers will perform the last four-millionth calculation with the same accuracy and speed as the first calculation.
In the initial stages of development computers used to be an isolate machine with the tremendous growth in computers technologies today’s computers have the capability to connect with each other, this has made the sharing of costly resources like printers possible apart from device sharing data and information can be shared among groups of computers thus creating a large information and knowledge base.
Application of computer:
Computers not only save time but it also saves paperwork some of the areas where a computer is being used are as follows:
Scientists have been using computers to develop theories and to analyses and test the data the high speed and accuracy of the computers allow different scientific analyses to be carried out they can be used generated detailed studies of satellite-based application have not been possible without the use of computer moreover it would not be possible to get the information of the solar system and the cosmos without computers.
A computer has also revolutionized the whole process of education currently the classrooms libraries and museums are efficiently utilizing computers to make the education much more interesting unlike recorded television shows computer-aided education(CAE) and computer-based training packages are making learning much more interactive.
Medicine and health care:
There has been an increasing use of computers in the field of medicine now doctors are using computers right from diagnosing the illness to monitoring a patients status during complex surgery by using automated imaging techniques doctors are able t look inside a person’s body and can study each organ in detail (eg CT scans or MRI scans) which was not possible few years ago.
Computers are finding greater use in the entertainment industry they are used to control the images and sounds the special effect that mesmerizes the audience would not have been possible without the computer in addition computerized animation and colorful graphics have modernized the film industry.
Email or electronic mail is one of the communication media in which computers are used through email messages and reports are passed from one person to one or more person with the aid of computer and telephone line the advantage of this service is that while transferring the messages it saves time avoids wastage of paper and so in moreover, the person who is receiving the message can read the messages whenever he is free and can save it reply it forward it or delete it from the computers.
This is one of the important uses of the computers initially computers were used for batch-processing jobs where one does not require the immediate response from the computers currently computers are mainly used for real-time application that requires immediate response from the computers there are various concerns where computers are used such as in business forecasting to prepare pay bills and personal records in banking operations and data storage in various types of life insurance business and as an aid to management, businesses are also using the networking of computers where a number of computers are connected together to share the data and the information use of email and the internet has changed the ways of doing business.
computers have created a field known as desktop publishing (DTP) in DTP with the help of computers and a laser printer one can perform the publishing job all by oneself many of the tasks requiring long manual hours such as making a table of contents and index can be automatically performed using the computer and DTP software.
computers are extensively used in the field of banking and finance people can use ATM(automated teller machine) services 24 hours a day to deposit and withdraw cash when different branches of the bank are connected through computer networks the inter-branch transactions such as cheque and draft can be performed without any delay.
Types of computer:
There are three different types of computers according to the principles of operation those three types of computers are given as under:
- Analog computers
- Digital computer
- Hybrid computers
Analog computer is a computing device that works on continuous range of values the results given by the analog computers will only be approximate since they deal with quantities that vary continuously it generally deals with physical variables such as voltage pressure-temperature speed etc result generated by these computers are not complete there may be any fractions values involve with results of these computers wall clocks are the main example of these computers.
On the other hand a digital computer operates on digital data such as numbers it uses binary number system in which there are only two digits 0 and 1 each one is called a bit.
The digital computer is designed using digital circuits in which there are two levels for an input or output signal these two levels are known as logic 0 and logic 1 digital computer can give more accurate and faster results. a digital computers is well suited for solving complex problems in engineering and technology hence digital computer have increasing use in the field of design research and data processing based on the purpose digital computers can be further classified in two main categories
- General-purpose computers
- Special purpose computers.
A hybrid computer combines the desirable features of analog and digital computers it is mostly used for automatic operations of complicated physical processes and machines nowadays analog to digital and digital to analog converters are used for transforming the data into a suitable form for either type of computation
For example, in hospital ICU analog devices might measure the patients temperature blood pressure and other vital signs these measurements which are in analog might then be converted into numbers and supplied to digital components in the system these components are used to monitor the patients vital sign and send signals if any abnormal reading is detected hybrid computers are mainly used for specialized tasks.
Classification of computer:
There are four different types of computers when we classify them based on their performance and capacity these types of computers are discussed as under:
- Mainframe computers
- Mini computers
- Micro computers
When we talk about types of computer the first type that comes to our mind would be supercomputers they are the best in terms of processing capacity and also the most expensive ones these computers can process billions of instructions per second normally they will be used for applications which require intensive numerical computations such as stock analysis weather forecasting etc other uses of supercomputers are scientific simulations graphics fluid dynamic calculations nuclear energy research electronic design and analysis of geological data perhaps the best-known supercomputer manufacturer is cray research some of the traditional companies which produce supercomputer are cray IBM and Hewlett Packard.
Mainframe computers can also process data at very high speed ie hundreds of million instructions per second and they are also quite expensive normally they are used in banking airline and railways etc for their application.
Minicomputer is lower to a mainframe computer in terms of speed and storage capacity they are also less expensive than mainframe computers some of the features of mainframe will not be available in mini computers hence their performance also will be less than of mainframe.
The invention of a microprocessor(single-chip CPU) gave birth to the much cheaper microcomputer they are further classified into different categories which are given as under:
- Desktop computers(personal computers)
- Laptop computers
- Handheld computers(PDAs)
For more information, you can study computer application author Engr.Zia Muhammad kakakhel