Input Devices
An input device is used to feed data into a computer. The human understandable form is converted into machine understandable form 0’s and 1’s
Examples: Keyboard, Mouse, Joystick, OCR, MICR etc.

Keyboard
The most common input device is the keyboard. Keyboard consists of keys such as alphabetic keys to enter letters, numeric keys to enter numbers, punctuation keys to enter special symbols and function keys to perform some specific functions.

Keyboard types:
1)      Standard Keyboard
2)     Ergonomics Keyboard
3)      Wireless Keyboard
4)      Virtual Keyboard
5)      Compact Keyboard.

Mouse
A device used to move a cursor on a computer screen and interact with graphical user interfaces. It typically has one or more buttons and can be moved across a flat surface. 

Computer Mouse comes in different types:
1) Manual Mouse RJ
2) Scroll Mouse
3) USB Mouse
4) Wireless Mouse

Joystick
A joystick is an input device consisting of a stick that pivots on a base and reports its angle or direction to the device it is controlling. 
Joysticks are often used to control video games, simulated programs, usually have one or more push-buttons whose state can also be read by the computer.

Optical Mark Reading and Recognition (OMR)
OMR is an input device. OMR stands for Optical Mark Recognition. It’s a technology used to detect and interpret marks made on a printed document, typically in the form of bubbles or checkboxes. 

Optical Character Recognition (OCR)
OCR stands for Optical Character Recognition. It’s a technology that enables the conversion of different types of documents, such as scanned paper documents, PDF files, or images captured by a digital camera, into editable and searchable data.

Magnetic Ink Character Recognition (MICR)
MICR stands for Magnetic Ink Character Recognition. It’s a technology used primarily in banking to facilitate the processing of checks. MICR encoding involves printing characters on documents such as checks using special ink that contains iron oxide particles. These characters can then be easily recognized and processed by high-speed magnetic ink character recognition devices.

Output Devices
Output is the result/information that is obtained after processing. The information must be presented in the human understandable form (usually from 0’s and 1’s to English/Kannada or any other language) is capable of presenting information on to the output devices.

Monitor
monitor is an output device used to present visual information generated by a computer. It’s essentially a screen that allows users to view images, videos, text, and other graphical content.
Types of monitor :
1) CRT(Cathode Ray Tube)
2) LCD(Liquid Crystal Display)
3) TFT(Thin Film Transistor)
4) LED(Light Emitting Diode)

Printer
Printer is an output device that prints text or images on paper or other media (like transparencies). By printing you create what is known as a ‘hard copy’.

The two main types of printers are impact printers and non-impact printers.
Impact Printers: This type of printer makes noise while printing due to striking effect. The print head has physical contact with paper while printing. Its speed is less and does not generate high quality output. It is generally used for applications such as billing document etc.,
Daisy Wheel Printers: This is impact printer, it uses printing mechanism which looks like daisy. Its speed is usually 25-50 words per second.
Line printers: This printer prints a whole line at once, and the speed is between 1000 to 6000 lines per minute.
Dot matrix printers: This printer uses 9-24 pin print head. It is usually in expensive and speed ranges between 100 to 550 character per second.

Non-Impact printer: In this type of printer there is no striking mechanism. Therefore it does not make noise while printing. It can print different colours, fonts, picture etc.,
Inkjet printer: This printer produces the output by spraying ink through ink nozzles present in the print head. It stores the ink in cartridges, and uses separate cartridge to print several types of color documents. It can generate colour prints with high quality. It is widely used in commercial application.
Laser printer: This printer uses laser beam and powdered ink for printing. It can print entire page at a time. It is also called as page printer. It generates high quality output. The printer has the buffer space to keep the data for printing.
LED Printers: LED Printers are quite similar to Laser Printers, but it uses LED instead of laser to create pictures/images. LED printers are considered are more efficient and reliable than laser printers.  

Plotters- A plotter is a graphical output device. It looks like a printer. It is used for printing large amount of data with drawings and pictures. It prints faster and helpful for industries to print calendar, poster, banner and many other types. Types of plotters are pen plotter, inkjet plotter, electrostatic plotter and thermal plotter.

Speaker: A speaker is an output device connected to audio port in a system. Speaker is used to listen to a music, to play games, movies etc. 

Memory Devices
Memory device refers to any physical device or medium used to store, retrieve, and retain digital data. These media come in various forms and technologies, each with its own characteristics, advantages, and limitations.