Saminshakya21powerpoint of computer and its components .pptx

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1. Introduction to Computer The modern world is called the age of science and technology. We cannot imagine life without science and technology. The modern world of advanced technology could not have been established without the development of computer technology. There is rapid development in computer. Computer is used in many different fields for varieties of tasks. It is used all over the world, no matter whether a country it is developed, developing or underdeveloped. Computer is also used in Nepal various fields like: business, bank, education, entertainment, scientific research, law, airlines, traffic control, etc. So, the computer is now affecting every sphere of human activities and leading to many changes. It has brought enormous changes in the world.

2. Introduction The word "Computer" is derived from the Latin word " Computare " which means 'to calculate'. Nowadays, computer has become an indispensable part of our life. Computer is used in various places like: home, school, college, offices etc. Computer can perform complex mathematical calculations accurately in a short period of time. The modern computer has lots of capabilities like creating documents, videos, games, music presentation, etc. It can use AI (Artificial Intelligence) for understanding natural language, taking self-decision capabilities, analysing graphs and patterns, etc.

3. Working Principle of a Computer Computer is an electronic device that converts raw data into meaningful information carrying out various processes as instructed by the programme Every computer has the ability to : a . Input: Enter raw data into the computer. b. Process: Process according to the given set of instructions to produce the required result. c. Output: Get meaningful information from the computer. d. Storage: Store data and information for future use.

4. Characteristics of a Computer A computer is powerful and useful in all areas. The use of computer is increasing with time. The main features or characteristics of computer are described below: i . Automatic A computer is an automatic device. It can do tasks automatically as instructed by software. It can automatically control various devices attached with computer system. ii. Speed A computer performs tasks accurately. The operations on data in computer are performed through electronic circuit according to given instructions. Computer can perform millions and billions of operations on data within a second. The speed of computer is measured in Megahertz (MHz) or Gigahertz (GHz). The time taken to perform a task is measured in fraction of second. The smaller units of second are given below:

5. iii. Accuracy A computer performs t4asks accurately. If data and instructions given to the computer are correct then it gives an accurate output. It means output totally depends on the given instructions and input data. If input data is incorrect then the output will be incorrect which is called GIGO (Garbage in Garbage out). iv. Storage Computer system consists of data storage unit. A computer has main storage and secondary storage. A large amount of data can be stored in secondary storage like hard disk, pen drive, CD/DVD, etc. for future use. The main memory (RAM) stores currently used data. v. Diligence A computer can continuously work for a long time without losing its speed and accuracy. So it is called diligent device. It doesn’t get tired or bored or lazy while working.

6. vi. Versatile A computer is a versatile device which means it is flexible. It has capability of performing different types of tasks like drawing paints, playing games,music , calculations, sending an e-mail, desktop publishing work, etc. in different field efficiently. So it is used in different fields to perform varieties of tasks . The main components of computer system are defined below: a. Data: Data is the main part of computer system. It can be processed to get desired output as information. b. Software: A set of programs are called software which instructs the hardware to perform a task. For example MS Windows, MS Word, MS Excel, etc. c. User: The person who operates computer system is called a user. d. Hardware: The physical parts of a computer which can be touched, seen and felt are called computer hardware. For example Keyboard, mouse, monitor, etc.

7. The computer hardware is further divided into four units: a. Input unit b. Process unit c. Output unit and d. Storage unit a. Input Unit This unit enters data into the computer. An input unit consists of input devices like keyboard, mouse, microphone, joystick, etc. These devices are used to enter data and instructions or commands into computer system. Input unit acts as a communication channel between user and computer. The input devices translate the information into a form understandable by the computer.

8. b. Processing Unit A processing unit consists of processing devices like CPU (Central Processing Unit). CPU is the main processing unit of a computer system. It is also known as the brain of computer system. It receives data from input unit, processes it as instructed by the user and produces information as output. The speed of CPU is measured in hertz. Hertz is also called CPU clock rate or CPU clock speed. Nowadays, CPU speed is measured in Gigahertz (GHz). 1 GHz = 1000 MHz (Megahertz). = 1,000,000 KHz (Kilo Hertz). = 1,000,000,000 Hz (Hertz). So, one Gigahertz is equal to one billion hertz. The CPU speed of 2.1 GHz is equal to 2.1 *1,000,000,000 Hertz .

9. The CPU consists of the three main parts. i . CU (Control Unit), ii. ALU (Arithmetic Logic Unit) and iii. MU (Memory Unit- Register Array) i . Control Unit Control Unit is a part of the CPU that controls and coordinates activities of other units of computer system. It acts as a nervous system of computer. It controls the execution of instructions given to system. It coordinates the flow of data in or out of ALU, memory and various input or output devices. ii. Arithmetic Logic Unit Arithmetic logic unit is a part of CPU that can perform arithmetic operation like addition, subtraction, multiplication and division. It also performs logical comparison like equal to, greater than, less than, etc. to compare between two numbers.

10. iii. MU (Memory Unit- Register Array) Memory unit is also a part of CPU but not the part of main memory that store currently executing task. It is located inside the microprocessor and has very limited storage. It is used to store very active data and instructions temporarily during processing. c. Output Unit An output unit consists of output devices like monitor, printer, speaker, etc. These devices are used to display information after processing raw data from the processing unit.

11. d. Storage Unit A storage unit consists of primary and secondary storages. The primary storage or main storage stores raw data and instruction. RAM (Random Access Memory) and ROM (Read Only Memory) are the examples of storage unit.The functions of the storage unit are below.  It stores intermediate results of processing.  It stores all the data and the instructions required for processing.  It stores the final results of processing before these results are released to an output device. The secondary storage stores processed or unprocessed data or information for future use. Hard disk, pen drive, CD, DVD, etc. are the examples of the storage unit.