Computer
A computer is an advance electronic machine that accepts input from the users, processes the given data by performing defined operations on it, and generates the output in the form of useful information. They can store large volumes of information in the form of binary code and process it at a very high speed and accuracy to produce the desired result.
Following are the basic working principle of a computer:
- It accepts raw data and instructions through the input device such as keyboard, mouse, webcam, etc.
- The data entered are processed by the processing unit i.e. CPU.
- After processing it provides the desired output to the user through various output devices such as monitor, speaker, printer, etc.
The working principal of computer can be summarized as Input, Processing and Output devices such as monitor, speaker, printer, etc.:
- Input:
This is the stage where data is entered into the computer system. Input can come from various sources such as keyboards, mice, touchscreens, scanners, sensors, and even other computers over a network. The data entered could be text, numbers, images, or any other form of digital information.
Keyboard:
A computer keyboard is an input device used to enter characters and functions into the computer system by pressing keys. It is the primary device used to enter input or text. A keyboard typically contains keys for individual letters, numbers and special characters, as well as keys for specific functions.
Keys and their description
| S.NO | Keys and Description |
| 1 | Typing keys
These keys include the letter keys (A-Z) and digit keys (0-9) which generally give the same the same layout as that of typewriters. |
| 2 | Numeric keypad
It is used to enter the numeric data or cursor movement. Generally, it consist of a set of 17 keys that are laid out in the same configuration used by most adding machines and calculators. |
| 3 | Function keys
The twelve function keys are present on the keyboard which are arranging in row at the keyboard. Each function key has a unique meaning and is used for some specific purpose. |
| 4 | Control key
These key provide cursor and screen control. It includes four directional arrow keys. Control keys also include home, end, insert, delete, page up, page down, control, alternate, escape. |
| 5 | Special purpose keys
Keyboard also contain some special keys such as enter, shift, caps lock, num lock, space bar, tab, and print screen. |
Mouse:
A pointing device that allows users to interact with graphical user interfaces by moving a cursor on the screen and clicking on objects is called mouse or A mouse is a small device that a computer user pushes across a desk surface in order to point to a place on a display screen and to select one or more actions to take from that position.
Advantages
- Easy to use
- Not very expensive
- Moves the cursor faster than the arrow keys of the keyboard
Scanner:
A scanner is a device that allows you to digitize physical documents, images, or even objects, and convert them into a digital format that can be viewed, edited, and stored on a computer. It’s like a digital photocopier that captures the content of a document or image and saves it as a file.
Digital camera:
The term digital camera refers to a camera that creates digital images that may be printed, stored on a computer, and viewed on a screen. Webcam is one of the best example of digital camera. A webcam is a digital camera that captures video and audio data and transmits it in real-time over the internet.
- Process:
Once the data is inputted into the computer, it undergoes processing. This involves the computer’s CPU (Central Processing Unit) performing various operations on the data according to the instructions provided by software programs or applications. These operations could include calculations, comparisons, sorting, searching, and many others. Essentially, this stage involves manipulating the input data to produce meaningful results.
Control Unit
This is the core unit which manages the entire functioning of the computer device. It is one of the most essential components of the computer system. The Control Unit collects the data entered using the input unit, leads it on for processing and once that is done, receives the output and presents it to the user. It can be said to the centre of all processing actions taking place inside a computer device.
Arithmetic and logic unit
ALU is a part of CPU which performs arithmetic and logical operations on the data. The arithmetic operation can be addition, subtraction, multiplication and division and also the logical operator such as less than, greater than, smaller than, AND, OR, NOT.
- Output:
After the data has been processed, the results are produced as output. Output can take various forms depending on the nature of the processed data and the intended audience. Common output devices include monitors, printers, speakers, and storage media. The output could be in the form of text, images, sounds, videos, or any other format that conveys the processed information to the user.
Monitor/Display:
The most common soft copy output device, which displays text, graphics, and multimedia content on a screen.
CRT (Cathode Ray Tube) Monitor:
CRT monitors were the standard for many years before LCD and LED displays became prevalent. They work by using a cathode ray tube to display images. CRT monitors are bulky and heavy due to the technology they use. They are gradually becoming obsolete as LCD and LED technologies offer better picture quality and energy efficiency.
LCD (Liquid Crystal Display) Monitor:
LCD monitors replaced CRT monitors as the standard display technology for computers and TVs. They use a layer of liquid crystal solution sandwiched between two sheets of glass. When an electric current passes through the liquid crystals, they align to control the amount of light passing through and thus create the image. LCD monitors are thinner and lighter compared to CRT monitors. They consume less power and produce less heat than CRT monitors. LCD technology has evolved over time, with improvements in resolution, response time, and colour accuracy.
LED (Light Emitting Diode) Monitor:
LED monitors are a type of LCD monitor that uses LED backlighting instead of the traditional fluorescent tubes used in older LCD monitors. LED backlighting offers several advantages, including higher energy efficiency, better contrast ratios, and longer lifespan. There are two main types of LED backlighting: edge-lit and direct-lit. Edge-lit LED monitors have LEDs along the edges of the screen, while direct-lit LED monitors have LEDs spread across the entire back of the screen. LED monitors are thinner and lighter than both CRT and traditional LCD monitors. They offer better colour accuracy and brightness compared to older LCD technology.