What is a computer?
A computer is an electronic device which can perform various arithmetic and logical operations automatically.
It takes the data as input and then manipulates it and perform the necessary operations and gives the output to the user.
Todays modern computers can perform sets of operations that can be known as programs. These programs helps the computer to perform wide range of tasks.
Parts of computer
There are many parts of computer system which helps us to input data and to render the data from computer.
The computer is mainly divided into three parts:
1. Input device
2. Output device
3. Central Processing Unit
1. Input devices :
These devices are used to input the data from the user and pass it to the central processing unit(CPU). Then the data is manipulated and the necessary operations are carried out automatically and the output is displayed on the monitor.
2. Output devices :
The output devices are used to render the output using the input data given by the user. The data after doing the necessary manipulations is shown on the output screen.
3. Central Processing Unit (CPU) :
This is reffered as the "brain" of the computer, without it a computer is just a waste box. This is the part where all the necessary manipulations and operations on the input data is done and the output is given. It is also used to store the data and controls the entire the computer system.
It also have the three parts:
a) Control device:
The control device controls all the processes of the computer that are running inside the central processing unit and manages the working of all the programs.
b) Memory:
The memory is the part which stores different types of data and instructions of the computer. Your various data like your photos and videos that you store in your computer are stored in the memory.
c) Arithmetic Logical Unit (A.L.U) :
As the name indicates "arithmetic" means the calculations and manipulations of the input data . Here all the the necessary functions to perform logical and comparative calculations are done.
Now lets talk about various input and output devices:
Input Devices:
1) Keyboard :
It is the most commonly used input device to input the data from the user. The layout is like a traditional typewriter and some additional keys are also given to do some more additional functions.
The keys on the keyboard are :
Typing Keys -
The typing keys include the letters from (A-Z) written in random format and it also includes the digits from(0-9). These typing keys are used to write the data in words using letters.
Control Keys -
These keys provide the cursor and screen control. It includes Home, End, Insert, Delete, Page up, Page down, Control(Ctrl), alternate(Alt), Escape(Esc).
Numeric Keys -
It is used to enter the data in the numeric form. It consists of a set of 17 keys consisting of numbers and arithmetic operations signs like addition, subtraction, Multiplication, Division.
Function Keys -
There are overall 12 function keys present on the Keyboard. Each key has a unique meaning and is used for special purpose.
Special Purpose keys -
The Keyboard also contains some Special Purpose Keys such as Enter, Num Lock, Space Bar, Tab, Caps Lock, Print Screen, Shift.
2) Mouse :
The mouse is known as the pointing device. Generally, it has two buttons called as left and the right button and the wheel between the buttons. It is used to control the position of the cursor on the monitor screen.
3) Scanner :
Scanner is a input device which works same as like Photocopy machine. It is used to convert the data on paper to digital form to store it in hard disk for further manipulations. The images are captured by the scanner and converted.
4) Microphone :
The microphone is also used as input device to input the sound and then converted in digital form. It is used in various applications to add sound or music.
5) Cameras :
It is used as a input device to input the photos and store it in the device. It is also used for video calls to show our face to the other person.
6) Bar code readers :
Bar code reader is a input device used to read the data written in the bar code form (in light and dark lines) . The bar codes are generally used for labelling various goods and products.
7) Light pen :
Light pen is a pointing device similar to a pen. It is used draw pictures on the monitor screen. It consists of a photocell and an optical system placed in small tube. The picture is drawn on screen because of its photocell sensing element which detects screen location and sends signalsto the CPU.
8) Joystick:
It is also known as the pointing device, which is used to move the position of the cursor on the screen. It is a stick having a spherical ball at its both lower and upper ends. It can be moved in all four directions. It is mostly used in Computer Aided Design (CAD) and playing games.
Output Devices :
1) Monitor :
It is the main output device of a computer. The output after the manipulations of the input data is displayed on the monitor screen.the images are formed by converting the electrical energy into light in the form of tiny dots on the screen called pixels. Thats why the clearness of the image depends on the number of pixels.
2) Printer :
The printer is used to print the information present on the screen on paper. Mainly, it uses the lasers or the inkjets to place the ink on the paper precisely to recreate the text and the images. We can print the information or the data present on the output screen using the printer.
3) Speakers:
A speaker is a hardware output device connected with the computer to produce the audio. There is a sound card in the system which is preinstalled, and helps to produce the sound. The audio signal is sent through the computers sound card to produce the sound coming from a speaker.
4) Projector :
The projector is also a type of output device. It is used to project the output of the screen over the entire wall. Using the projector, we can cast information like audio, video, images and animation from a computer/laptop to the big screen.
5) Headphones :
Headphones are also a type of output device. They are also known as earphones. Through the headphones you can listen any audio privately after connecting it to a smartphone or computers. The main purpose of using the headphones is to listen the audio privately, mainly in a crowd, and avoid the disturbance.
6) Sound card :
Sound cards are the output devices of the computers that are preinstalled inside a computer. To produce any sound of computer you need to have a sound card externally or internally. It helps to generate higher quality and clear sound.
7) Video card :
The video card are also a type of output device. It is responsible for processing the data - machine code and translating into an accessible image. Nowadays, if you want to work on professional video processing programs, playing high definition games, designing videos you need an external video card.
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