(i) CRT- Cathode Ray Tube
(ii) LCD - Liquid Crystal Display
(iii) LED - Light Emitting Diodes

Natural Language Processing is the ability of a computer program to understand human language. It is a component of artificial intelligence.

Memory enables the computer to store the program. The memory unit is of two types:
(i) Primary memory
(ii) Secondary memory
The primary memory is used to store data temporarily and secondary memory stores the data permanently.

The control unit controls the flow of data between the CPU, memory I/O devices. It also controls the entire operations of a computer.

Computer is an Electronic Machine, capable of performing basic operations like addition, multiplication, division etc. Computer accepts data as input, process it, produce output and stores it for future.

Hardware are the physical components of a computer like a motherboard, memory devices, monitor, keyboard etc while the software is the set of programs or instructions. Both hardware and software together make the computer system function.

(i) POST (Power-On Self-Test) is the diagnostic testing sequence that a computer's basic input! output system runs to determine if the computer keyboard, random access memory, disk drives and other hardware are working correctly.
(ii) If the necessary hardware is detected and found to be operating properly, the computer begins to boot.

Monitor:
(a) A computer monitor is an output device which displays information in pictorial form.
(b) Monitors can be of monochrome which displays text or images in Black and white (or) in color.
(c) Different types of monitors are CRT, LCD and LED.

Optical Mouse	Laser Mouse
It is less sensitive towards the surface	Highly sensitive
Tracking power is less	Tracking power is more
Old technology	Latest technology
This uses the light source instead of ball to judge the motion of the pointer.	This uses Laser light
Optical mouse has 3 buttons	No. of buttons will vary from 3 to many

The Basic characteristics of the computers are:
(i) High speed
(ii) Stores Huge Data
(iii) They do millions of different tasks
(iv) Very versatile
(v) Accurate
(vi) Diligence

Registers:
(i) Registers are the high-speed temporary storage locations in the CPU. Hence, their contents can be handled much faster than the' contents of memory.
(ii) Although the number of registers varies from computer to computer, there are some registers which are common to all computers. Five registers that are essential for instruction execution are:
(iii) Program Counter (PC): Contains the address of the next instruction to be fetched.
(iv) Instruction Register (IR): Contains the instruction most recently fetched.
(v) Memory Address Registers (MAR): Contain the address of a location in memory for read and write operations.
(vi) Memory Buffer Register (MBR): It contains the value to be stored in memory or the last value read from memory.
(vii) Accumulator (ACC): An accumulator is a general purpose register used for storing temporary result produced by the arithmetic logic unit.

(i) Scanner:
Scanners are used to enter the information directly into the computer's memory. This device works like a Xerox machine. The scanner converts any type of printed or written information including photographs into a digital format, which can be manipulated by the computer.
(ii) Fingerprint Scanners: 
Fingerprint Scanner is a fingerprint recognition device used for computer security, equipped with the fingerprint recognition feature that uses biometric technology. Fingerprint Reader / Scanner is a very safe and convenient device for security instead of using passwords, which is vulnerable to fraud and is hard to remember.
(iii) Monitor:
Monitor is the most commonly used output device to display the information. It looks like a TV. Pictures on a monitor are formed with picture elements called PIXELS. Monitors may either be Monochrome which display text or images in Black and White or can be color, which display results in multiple colors. There are many types of monitors available such as CRT (Cathode Ray Tube), LCD (Liquid Crystal Display) and LED (Light Emitting Diodes). The monitor works with the VGA (Video Graphics Array) card. The video graphics card helps the keyboard to communicate with the screen. It acts as an interface between the computer and display monitor. Usually the recent motherboards incorporate built-in video card.
(iv) Plotter:
Plotter is an output device that is used to produce graphical output on papers. It uses single colour or multi colour pens to draw pictures.

(a) Inkjet Printer:
(i) Inkjet printer use colour cartridges which combined magenta, yellow and cyan inks to create colour tones.
(ii) A black cartridge is used for monochrome output. Inkjet printer works by spraying ionised ink at a sheet of paper.
(iii) The speed of inkjet printers generally range from 1-20 ppm (page per minute)
(iv) An inkjet printer can spread millions of dots of ink at the paper every single second.
(v) They use the technology of firing ink by heating it so that it explodes towards the paper in bubbles or by using piezo electricity in which tiny electric currents are controlled by electronic circuits.
(b) Multimedia Projector:
(i) Multimedia projectors are used to produce computer output on a big screen.
(ii) These are used to display presentations in meeting halls or in class rooms.
(c) Barcode/ QR code Reader:
(i) A Bar code is a pattern printed in lines of different thickness.
(ii) The Bar code reader scans the information on the bar codes transmits to the computer for further processing.
(iii) The system gives fast and error free entry of information into the computer.
Quick response (QR) code:
The QR code is the two dimension bar code which can be read by a camera and processed to interpret the image.

(i) Basic components of computer :
The Basic components are I/O Unit, CPU, ALU, Control Unit, Storage Unit.
Input unit:
Input unit is used to feed any form of data to the computer. It can be stored in the memory unit for further processing.
Ex. Keyboard, Mouse, Scanner, Retinal scanner, Track ball.
Central processing unit:
CPU is the major component and it controls the operation of all other components such as memory, input and output units. The CPU has three components namely control unit, Arithmetic and logic unit (ALU) and memory unit.
Arithmetic and logic unit:
The ALU is a part of the CPU where arithmetic operations like addition, subtraction, multiplication, divisions and logical operations will takes place.
Control unit:
The control unit controls the flow of data between the CPU, memory and I/O devices. It also controls the entire operation of a computer.
Output unit:
An output device is a hardware component that conveys information to the user in an understandable form.
Ex. Monitor, printer, plotter
Memory unit:
The memory stores everything that computer works with. The memory unit is of two types namely primary memory and secondary memory. The primary memory stores the data and instructions temporarily. Whereas the secondary memory stores the data permanently. The primary memory is volatile and secondary memory is non-volatile.