Input and output devices are essential components of a computer system, allowing users to interact with and receive information from the machine. These input/output devices are also known as peripherals since they surround the CPU and memory of a computer system.
Input Devices
Input Devices is any hardware component that allows user to enter data and instruction into a computer system. These devices convert the input data into a digital form that is acceptable by the computer system. Some examples of input devices include keyboard, mouse, scanner, touch screen,microphone etc.
Examples of Input Devices:
Keyboard
A keyboard is an input device that allows users to enter text, numbers, and commands into a computer. The most common keyboard layout is the “QWERTY” keyboard. The different keys present in the keyboard are:
- Alphabet keys – A-Z
- Numeric Keys – 0-9
- Function Keys – F1, F2 ….. F12
- Special Purpose Keys – Shift, Delete, Alt, Enter, Ctrl
- Arrow keys →, ↓, ←, ↑
- Optical Mouse
- Laser Mouse
- Wireless Mouse
- Gaming Mouse
- Trackball Mouse
Handheld Scanner: A Handheld Scanner is a portable, lightweight scanner that the user manually moves over the surface of an item to scan it. It uses optical sensors (e.g., CCD or CIS) to capture light reflected off the scanned surface. Barcode scanner is one of the example of handheld scanner.
OCR (Optical Character Recognition): OCR is a technology that converts images of text into machine-readable and editable text.A scanner captures an image of a page, and OCR software identifies letters, numbers, and symbols, turning them into text you can edit or search. It’s especially useful for automating data entry and preserving documents in a digital format!
OMR (Optical Mark Recognition): OMR is a technology used to detect and read marks on a printed form or sheet. It is commonly used for automated data collection from surveys, exams, and voting ballots. It is widely used for processing multiple-choice exams, surveys, ballots, or forms where specific areas are marked. OMR is fast, accurate, and efficient, making it ideal for processing large volumes of structured data.
MICR (Magnetic Ink Character Recognition): MICR is a technology that reads and process printed information using special magnetic ink. It is primarily used in the banking sector for processing cheques and other financial documents securely and efficiently.
Joystick: A joystick is an input device used to control the movement or actions of a virtual or physical object. It typically consists of a handheld stick that pivots on a base, along with buttons, triggers, or other controls. When the stick is moved or buttons are pressed, electrical signals are sent to a connected device (e.g., a computer, console, or machine) to translate the input into actions. Joysticks are commonly used in video games, flight simulators, and assistive technology.
Output Devices
An output device is a hardware component that receives data from a computer and converts it into a form that a user can understand or use such as text, images, sound, or video. It allows the computer to communicate information to the user.
Example of Outpur Devices:
Monitor
A monitor is an electronic output device used to display visuals information such as text, images, and videos from a computer. Monitors, also known as Visual Display Units (VDUs).
Types of Monitors
CRT Monitors (Cathode Ray Tube)
A CRT (Cathode Ray Tube) monitor is an older type of computer display that uses a vacuum tube and electron beams to produce images on a phosphorescent screen. A CRT monitor contains a vaccum tube with three electron guns (Red, Green, and Blue) that emits a beam of electrons. These electron beams are then deflected by electromagnetic fields, allowing them to scan across the screen. When the electron beams hit the phosphor coating on the screen, the phosphor glows, creating the image.
- Bulky and heavier compared to modern flat-screen monitor
- Lower resolution compared to LCD and LED monitors.
- Consumes more power and generates more heat.
LCD (Liquid Crystal Display)
LED monitor is a type of flat-panel display that uses light-emitting diodes as the backlight source to illuminate the screen. Just like LCD, LED screens use liquid crystals to form images. Instead of fluorescent tubes, tiny LEDs provide light, improving brightness and energy efficiency.
Difference between LCD and LED
LED monitors are better because they are brighter, energy-efficient, and have a longer lifespan.
Printers
A printer is an output device that converts digital data (text, images, or graphics) into physical copies on paper. It connects to computers, smartphones, or networks to produce hard copies of digital content.
Types of Printers
Dot Matrix Printers
Dot Matrix Printers are a type of impact printer that create characters and images by striking an ink-soaked ribbon against paper using a grid of tiny pins.
- Its speed is usually 30 to 550 characters per second (cps).
- It is cheapest and the most noisy printer and has a low print quality.
- Daisy wheel printers were known for producing high-quality text
- Produces sharp and clear text, similar to typewriters.
- Can only print text, not images or graphics.
- The mechanical striking action is loud.
Inkjet Printer
An Inkjet Printer is a non-impact printer that sprays tiny droplets of liquid ink directly onto paper to create images and text. It is commonly used for home, office, and photo printing due to its affordability and high-quality color output.
- it deliver high-quality output, excelling in photos, graphics, and vibrant, detailed color documents.
- use ink cartridges
- Minimal noise compared to dot matrix or daisy wheel printers.
- Cartridges can be expensive and need frequent replacement.
- Not ideal for high-volume printing.
- It prints much faster than inkjet printers.
- lower cost per page compare to inkjet
- Ideal for professional documents and reports.
- use toner cartridges
- Larger and heavier than inkjet printers.
- Takes a few seconds to heat up before printing.
- Toner cartridges last longer than ink cartridges.