A computer is a programmable electronic device that accepts raw data as input and processes it according to programmed instructions to produce output. It consists of hardware components like the CPU, memory, and storage that perform logical and arithmetic operations on data, as well as software programs and operating systems. The basic components of a computer are the input unit, memory unit, central processing unit, and output unit, which work together in a continuous loop of input, processing, and output via the IPO cycle.

1. restaurant is data – this becomes information when the business is able to identify
the most popular or least popular dish.
What is Computer
A computer is a programmable electronic device that accepts raw data as input and
processes it with a set of instructions (a program) to produce the result as output. It
renders output just after performing mathematical and logical operations and can
save the output for future use. It can process numerical as well as non-numerical
calculations. The term "computer" is derived from the Latin word "computare"
which means to calculate.
A computer is designed to execute applications and provides a variety of solutions
through integrated hardware and software components. It works with the help of
programs and represents the decimal numbers through a string of binary digits. It also
has a memory that stores the data, programs, and result of processing. The
components of a computer such as machinery that includes wires, transistors, circuits,
hard disk are called hardware. Whereas, the programs and data are called software.

2. The IPO cycle is defined as a computer procedure for the processing of
information. In computation, it is a critical process through which users get the
desired outcome.
 It comprises mainly of three elements; input, process, and output.
 Input is the necessity that either the user or any other source enters the
machine from the environment via input devices such as keyboards, and so
on.
 Processing is the calculation that the CPU conducts on the user’s demand.
 The output is the result that is given to the user via the monitor as per the
criteria.
 It is a continuous loop through which millions of users will generate the
results of their desired result.
Input Process Output

3. control computer’s operation, input and output. Examples of hardware are CPU,
keyboard, mouse, hard disk, etc.
Software: A set of instructions that drives computer to do stipulated tasks is called
a program. Software instructions are programmed in a computer language, translated
into machine language, and executed by computer. Software can be categorized into
two types −
 System software
 Application software
System Software
System software operates directly on hardware devices of computer. It provides a
platform to run an application. It provides and supports user functionality. Examples
of system software include operating systems such as Windows, Linux, Unix, etc.
Application Software

4. Input Unit
•The computer accepts the information in the form of program & data through an
input device. Eg: keyboard
•Whenever a key is pressed, the corresponding letter/digit is automatically
translated into its corresponding binary-code and transmitted over a cable to either
the memory or the processor.
Memory Unit
• This unit is used to store programs & data.
•There are 2 classes of storage: 1) Primary-storage is a fast-memory that operates
at electronic-speed. Programs must be stored in the memory while they are being
executed. 2) Secondary-storage is used when large amounts of data & many
programs have to be stored. Eg: magnetic disks and optical disks(CD-ROMs).

5. • Timing-signals are signals that determine when a given action is to take place.
Output Unit
•This unit is used to send processed-results to the outside world. Eg: printer,
graphic displays etc.
Computer Memory
The computer memory holds the data and instructions needed to process raw data
and produce output. The computer memory is divided into large number of small
parts known as cells. Each cell has a unique address which varies from 0 to memory
size minus one.
Computer memory is of two types: Volatile (RAM) and Non-volatile (ROM). The
secondary memory (hard disk) is referred as storage not memory.
But, if we categorize memory on behalf of space or location, it is of four types:
o Register memory

6. Primary Memory
Primary memory holds only those data and instructions on which the computer is
currently working. It has a limited capacity and data is lost when power is switched
off. It is generally made up of semiconductor device. These memories are not as
fast as registers. The data and instruction required to be processed resides in the
main memory. It is divided into two subcategories RAM and ROM.
RAM (Volatile Memory)

7. DRAM, unlike SRAM, must be continually refreshed in order to maintain the data.
This is done by placing the memory on a refresh circuit that rewrites the data several
hundred times per second. DRAM is used for most system memory as it is cheap and
small. All DRAMs are made up of memory cells, which are composed of one
capacitor and one transistor.
ROM (Non-volatile Memory)
It is a non-volatile memory. It means it does not lose its data or programs that are
written on it at the time of manufacture. So it is a permanent memory that contains
all important data and instructions needed to perform important tasks like the boot
process.
PROM (Programmable Read Only Memory)
PROM is read-only memory that can be modified only once by a user. The user buys
a blank PROM and enters the desired contents using a PROM program. Inside the
PROM chip, there are small fuses which are burnt open during programming. It can
be programmed only once and is not erasable.

8. Some of the popular input devices are:
1) Keyboard
The keyboard is a basic input device that is used to enter data into a computer or any
other electronic device by pressing keys. It has different sets of keys for letters,
numbers, characters, and functions. Keyboards are connected to a computer
through USB or a Bluetooth device for wireless communication.

9. movement of the mouse and sends corresponding signals to the CPU when the
mouse buttons are pressed.
Generally, it has two buttons called the left and the right button and a wheel is
present between the buttons. A mouse can be used to control the position of the
cursor on the screen, but it cannot be used to enter text into the computer.
Joystick
Joystick is also a pointing device, which is used to move the cursor position on a
monitor screen. It is a stick having a spherical ball at its both lower and upper ends.

10. Track Ball
Track ball is an input device that is mostly used in notebook or laptop computer,
instead of a mouse. This is a ball which is half inserted and by moving fingers on
the ball, the pointer can be moved.
Since the whole device is not moved, a track ball requires less space than a mouse.
A track ball comes in various shapes like a ball, a button, or a square.
Scanner

11. This reading process is called Magnetic Ink Character Recognition (MICR). The
main advantages of MICR is that it is fast and less error prone.
Scanner captures images from the source which are then converted into a digital form
that can be stored on the disk. These images can be edited before they are printed.
Optical Character Reader (OCR)
OCR is an input device used to read a printed text.

12. The CRT display is made up of small picture elements called pixels. The smaller the
pixels, the better the image clarity or resolution. It takes more than one illuminated
pixel to form a whole character, such as the letter ‘e’ in the word help.
A finite number of characters can be displayed on a screen at once. The screen can
be divided into a series of character boxes - fixed location on the screen where a
standard character can be placed. Most screens are capable of displaying 80
characters of data horizontally and 25 lines vertically.
There are some disadvantages of CRT −
 Large in Size
 High power consumption
Flat-Panel Display Monitor
The flat-panel display refers to a class of video devices that have reduced volume,
weight and power requirement in comparison to the CRT. You can hang them on
walls or wear them on your wrists. Current uses of flat-panel displays include
calculators, video games, monitors, laptop computer, and graphics display.

13.  Very noisy
 Useful for bulk printing due to low cost
 There is physical contact with the paper to produce an image
These printers are of two types −
 Character printers
 Line printers
Character Printers
Character printers are the printers which print one character at a time.
These are further divided into two types:
 Dot Matrix Printer(DMP)
 Daisy Wheel
Line Printers
Line printers are the printers which print one line at a time.
These are of two types −

14. entertainment, etc.
Home
Computers are used at homes for several purposes like online bill payment, watching
movies or shows at home, home tutoring, social media access, playing games,
internet access, etc. They provide communication through electronic mail. They help
to avail work from home facility for corporate employees. Computers help the
student community to avail online educational support.
Medical Field
Computers are used in hospitals to maintain a database of patients’ history,
diagnosis, X-rays, live monitoring of patients, etc. Surgeons nowadays use robotic
surgical devices to perform delicate operations, and conduct surgeries remotely.
Virtual reality technologies are also used for training purposes. It also helps to
monitor the fetus inside the mother’s womb.
Entertainment
Computers help to watch movies online, play games online; act as a virtual
entertainer in playing games, listening to music, etc. MIDI instruments greatly help

15. In the banking sector, computers are used to store details of customers and conduct
transactions, such as withdrawal and deposit of money through ATMs. Banks have
reduced manual errors and expenses to a great extent through extensive use of
computers.
Business
Nowadays, computers are totally integrated into business. The main objective of
business is transaction processing, which involves transactions with suppliers,
employees or customers. Computers can make these transactions easy and accurate.
People can analyze investments, sales, expenses, markets and other aspects of
business using computers.
Training
Many organizations use computer-based training to train their employees, to save
money and improve performance. Video conferencing through computers allows
saving of time and travelling costs by being able to connect people in various
locations.
Arts

16. reservation system, gas subsidy disbursal, etc.
Multimedia and Entertainment
Multimedia refers to combination of text, audio, video, graphics, animation, etc. It
is one of applications of IECT. Multimedia is used to improve quality of presentation
by incorporating information sharing, usage of graphics and animation, motion
capture, etc.