Computer | Input Devices > Mouse > Keyboard > Digital Camera | CPU (Central Processing Unit)


Computer

Computer is an electronic device that manipulates the data & instructions then processes and give the desired result or computer is an electronic machine that can solve problems by accepting data as Input, performing certain operations and presenting the results of those operations as Output under the direction of detailed step-by-step instructions. Computer needs software to operate. Without it computer is of no use, the software that makes a computer work is called System Software or Operating System. Computer can perform arithmetic and logical operations, and also store data's in it for many days or years until it is deleted. Computer is being used in various fields like: Education, Defense, Medicine, Transportation, Communication to Different Countries, Banking, Science and Space Technology, Buying things or Programs, Entertainment, and many more.
In this 21st Century, we have to agree that there is no alternative for computer to lead human life so, the use of computer is increasing day-by-day. Computer has become the most integral part of our life. There is hardly any field of application where computer is not influenced. We need computer for better education, making our life easier by performing arithmetic and logical operations, and storing our important and valuable data's in it. It can also be used as entertainment because we can play many different kinds of games, and listen to songs and music. It has made our life easier, and comfortable to live.
So, it is now one of the important thing to be learned by everyone. Computer Science is the study of the operating principles of computer, programming languages for solving practical as well as theoretical problems on computer.
Computer performs IPO Cycle to show the results done by the user. Computer performs IPO Cycle by collecting the instructions entered into the computer from Input devices like: Keyboard, Mouse, etc. as input and then the computer manipulates the data as per given instruction known as processing and at last the result is obtained from the computer system to the output devices like: Monitor, Printer, etc. which will be in the form that people can understand and use such as words or pictures.
Computer performs various operations quickly, accurately and in efficient way without getting tired. So computer can work at very high speed without making any mistake, it can store large volume of data that can be used for future use, it does it’s work automatically once the instructions is given, it can be used in various fields like calculating, designing, word processing without getting tired for many hours. Since computer can do all these things it is a reliable machine.
As human beings have one brain as processing device and numbers of input and output devices for communication. Computer also has one processing device called Central Processing Unit (CPU) and other input and output devices. These Input/Output (I/O) devices which are connected to the computer are hardwares which provides means of communication between user and computer.
Softwares are set of programs needed to perform a certain task instructed by the user and hardwares are the physical components of the computer which can be touched and felt. It is needed to send/ receive and process instructions given by the user. So, without the presence of any one of these a computer is incomplete or cannot be operated. These two aspects of computer (Hardware and Software) are combined together to form a complete computer system.


Input Devices

Input devices transfer instruction or signals send by the user into the computer. The instructions or signals are converted by the device into electrical signals which are transmitted to the Central Processing Unit of the computer. Some input devices are Mouse, Keyboard, Scanner, Digital/Web Camera, Joysticks, Track Ball, Light pen, Touch Screen, etc.

Mouse

Mouse is a pointing input device which lets you select option from the screen by clicking on buttons. Mouse moves with the help of roller ball or with a light source and photo detector. It is easy to use because we can give instructions to the computer by clicking buttons.

Keyboard

Keyboard is the most common and important input device. Without it a computer cannot work. It is used to give instructions, data and commands. A keyboard contains all alphabetical letters with different symbols, numbers, modifier keys, function keys, arrow keys, and special purpose keys and many other shortcut keys.

Digital Camera

Digital Camera is a camera that stores photographed images electronically. A digital camera uses a CCD (Charge-Coupled Device) element to capture image through the lens. As computer stores it’s data in hard disk, the digital camera stores the captured image into a storage medium. The stored image can be downloaded by the USB Cable to store the it in the computer by using the software supplied with the camera. It’s main importance is to capture images and then store it in computer. The image can be then manipulated and processed like the image scanned from a scanner. It can now be easily edited in computer and can be printed as output form.

CPU (Central Processing Unit)

The main part of the computer system which controls and processes overall operation of the computer system is known as CPU (Central Processing Unit). It controls all internal and external devices so it is responsible for all the events inside the computer. It performs arithmetic and logical operations by the help of co-processor. Without the co-processor it is not possible to perform calculations. The CPU is the device that interprets and executes instructions as commanded. The CPU is composed of two units, namely: ALU (Arithmetic and Logic Unit) and CU (Control Unit).

Arithmetic and Logic Unit is the part where actual computations/calculations take place. The calculations/arithmetic operations are computed inside the CPU by the help of ALU over data received from memory. Calculations like addition, subtraction, multiplication, division, conversion of one number system to another number system refers to arithmetic operations. Control Unit directs and controls the activities of the internal and external devices. It is responsible for the movement of data’s and instruction’s in and out of the memory and CPU. It co-ordinates all system operations. All the computer resources are managed by Control Unit. It controls I/O (Input/Output) operations and guides the sending of data between the memory and Arithmetic and Logical operations.