Computer Fundamentals

Computer

A computer is a machine that manipulates data according to a set of instructions called a computer program. The program has anexecutable form that the computer can use directly to execute the instructions. The same program in its human-readable source codeform, enables a programmer to study and develop the algorithm. Because the instructions can be carried out in different types of computers, a single set of source instructions converts to machine instructions according to the central processing unit type.

The execution process carries out the instructions in a computer program. Instructions express the computations performed by the computer. They trigger sequences of simple actions on the executing machine. Those actions produce effects according to thesemantics of the instructions.

Data

Data  are the quantities, characters, or symbols on which operations are performed by a computer, being stored and transmitted in the form of electrical signals and recorded on magnetic, optical, or mechanical recording media. A programis a set of data that consists of a series of coded software instructions to control the operation of a computer or other machine.Physical computer memory elements consist of an address and a byte/word of data storage. Digital data can be reduced to key/value pair combinations. Supersets^] of this idea, where keys are derived, and values are arranged, relatively, are called data structures. They are also used in peripheral devices.

Characteristics of Computer

Speed, accuracy, diligence, storage capability and versatility are some of the key characteristics of a computer. A brief overview of these characteristics are—

• Speed The computer can process data very fast, at the rate of millions of instructions per second. Some calculations that would have taken hours and days to complete otherwise, can be completed in a few seconds using the computer. For example, calculation and generation of salary slips of thousands of employees of an organization, weather forecasting that requires analysis of a large amount of data related to temperature, pressure and humidity of various places, etc.
• Accuracy Computer provides a high degree of accuracy. For example, the computercan accurately give the result of division of any two numbers up to 10 decimal places.
• Diligence When used for a longer period of time, the computer does not get tired or fatigued. It can perform long and complex calculations with the same speed and accuracy from the start till the end.
• Storage Capability Large volumes of data and information can be stored in thecomputer and also retrieved whenever required. A limited amount of data can be stored, temporarily, in the primary memory. Secondary storage devices like floppy disk and compact disk can store a large amount of data permanently.
• Versatility Computer is versatile in nature. It can perform different types of tasks with the same ease. At one moment you can use the computer to prepare a letter document and in the next moment you may play music or print a document.

Computers have several limitations too. Computer can only perform tasks that it has been programmed to do. Computer cannot do any work without instructions from the user. It executes instructions as specified by the user and does not take its own decisions.

Applications of computers in various fields

Computers have their application or utility everywhere. We find their applications in almost every sphere of life–particularly in fields where computations are required to be done at a very fast speed and where data is so complicated that the human brain finds it difficult to cope up with.

As you must be aware, computer now-a-days are being used almost in every department to do the work at a greater speed and accuracy. They can keep the record of all the employees and prepare their pay bill in a matter of minutes every month. They can keep automatic checks on the stock of a particular item. Some of the prominent areas of computer applications are:

In Tourism: Hotels use computers to speed up billing and checkout the availability of rooms. So is the case with railways and airline reservations for booking tickets. Architects can display their scale models on a computer and study them from various angles and perspectives. Structural problems can now be solved quickly and
accurately.

In Banks: Banks also have started using computers extensively. Terminals are provided in the branch and the main computer is located centrally. This enables the branches to use the central computer system for information on things such as current balance,deposits, overdrafts, interest charges, etc. MICR encoded cheques can be read and sorted out with a speed of 3000 cheques per minute by computers as compared to hours taken by manual sorting. Electronic funds transfer (EFT) allows a person to transfer funds through computer signals over wires and telephone lines making
the work possible in a very short time.

Computers are finding their greatest use in factories and industries of all kinds. They have taken over the work ranging from monotonous and risky jobs like welding to highly complex jobs such as process control. Drills, saws and entire assembly lines can be computerized. Moreover, quality control tests and the manufacturing of products, which require a lot of refinement, are done with the help of computers. Not only this, Thermal Power Plants, Oil refineries and chemical industries fully depend on

computerized control systems because in such industries the lag between two major events may be just a fraction of a second.

In Transportation: Today computers have made it possible for planes to land in foggy and stormy atmosphere also. The aircraft has a variety of sensors, which measure the plane’s altitude, position, speed, height and direction. Computer use all this information to keep the plane flying in the right direction. In fact, the Auto–pilot feature has made the work of pilot much easy.

 In Education: Computers have proved to be excellent teachers. They can possess the knowledge given to them by the experts and teach you with all the patience in the world. You may like to repeat a lesson hundred times, go ahead, you may get tired but the computer will keep on teaching you. Computer based instructions (CBI) and Computer Aided Learning (CAL) are common tools used for teaching. Computer based encyclopedia such as Britannica provide you enormous amount of information on anything.

In Entertainment:Computers are also great entertainers. Many computer games are available which are like the traditional games like chess, football, cricket, etc. Dungeons and dragons provide the opportunity to test your memory and ability to think. Other games like Braino and Volcano test your knowledge.

1.  Input-output  Devices (Hardware,  Software, Human ware and Firmware)
2. 
   

1.   SOFTWARE

Computer consists of four basic element hardware, software, firmware and human ware. The hardware of computer system alone is little different to any other complex piece of electronic machinery. The hardware would not work without programs (set of instruction). The software directs and guides the operation of each device including CPU. The set of programs which control the activities of computer system or which may be processed on computer to do some useful work, are called software. As car needs fuel to run. Similarly computer hardware needs software to do anything. Software may be put on disk, cassette, and magnetic tape of Semi-Conductor memory.

So we can say that software is a set of programs documents procedure and routines associated with the operation of computer system. In other words, software means a collection of programs whose objective is to enhance the capabilities of the hardware.

1. 2.   Classification of software

Software cab be classified into two broad categories: System software and application software. System software performs computer- related tasks such as managing input and output devices; application software performs people- related tasks, such as human resources and marketing.

(I)                System software

(II)             Application software

SOFTWARE

SYSTEM SOFTWARE                                                              APPLICATION SOFTWARE

SYSTEM CONTROL S/W

SYSTEM SUPPORT S/W

SYSTEM DEVELOPMENT S/W

GENERAL PURPOSE S/W SPECIAL APPLICATION BASED S/W

                                                                   System Software

System software performs the basic functions necessary to start and operate a computer. It controls and monitors the various activates and resources of a computer and makes it easier and more efficient to use the computer. System software is classified into three categories.

1. System control software (Programs that manage system resources and functions)
2. System support software (Programs that support the execution of various application)
3. System development software (programs those system developers in designing and developing information systems).

(I)          System Control Software: System control includes programs that monitor, control, coordinate and manage the resources and functions of a computer system. The most important system software is the operating system and DBMS.

(II)       System Support Software: System support software is software that support or facilitates the smooth and efficient operation of a computer. There are four major categories of systems support software: Utility programs, language translators, database management systems and performance statistics software.

(III)     System Development Software: System development Software helps system developers design and build better system. An example is computer-aided software engineering or CASE a collection of programs that assist developers in developing information system.

                                                                   Application Software

Application software cab be divided into two categories: general purpose software and application dedicated software. Application software is designed to perform people-related tasks such as payroll, inventory and sales analysis. There are two type of application software: general-purpose (designed for general application, such as payroll and so on) and special Application Based Software.

1. 1.      General Purpose Software: General purpose software is used to perform common business applications such as word-processing graphics, payroll [and accounting].

1. 2.      Special Application Based Software: The second type of applications software is special application –Based software which includes specialized, application designed for every specific purpose. Such a program cannot easily be modified and adopted for other application because it is designed to perform a specific task. (Educational related application. Medical related application and Scientific application)

1. 3.   Hardware

Physical component of computer is called Hardware. Examples Monitor, Key-Board, Mouse, Printer etc.

1. 4.   Firmware

A programs by which perform the predefined instruction in machine memory called firmware. Example ROM, PROM, EPROM etc. ROM, PROM, EPROM

1. 5.   Humnware

The Human beings which is used the computer called human ware

,Advantages  and Limitations of Computer

Disadvantages: 1. It can have negative effects on your social life and interactions with other people if you do not maintain the balance between time online and offline. 
2. It may have a negative effect on your eyesight due to radiation. 
3. It may cause pimples and wrinkles. 
4. It may distract you from your studies. 
5. Too much time in front of monitor may adversely affect your eyesight. 
6. Sitting in front of a computer for too long without exercise can cause a weight gain.

7.A computer can only perform operations programmed or instructed by a person.

8. It cannot correct wrong instructions by itself.
9. Its capability to perform logical operations depends on the choice..

Advantages: 1. It helps you automate various tasks that you cannot do manually. 
2. It helps you organize your data and information. 
3. It has much more computing and calculating power then an ordinary human. 
4. It may help your work to be a lot easier. 
5. It can help you communicate with friends, coworkers and other contacts. 
6. It has many search engines to help you find information quickly.

7. It can store large amount of facts, instructions, and information.

8. It can process data with accuracy at a very high speed (reaching up to 50 million operations per second).
9. IT can repeat operations in exactly the same way over long period of time.
10. It can check the accuracy of its work.
11.It is capable of executing instructions on its own after the data and program have been fed into its memory.
12. It can perform logical operations.
13. It can communicate with the operator.