A computer is an electronic device that processes data into information and communicates the results through various input and output devices. The central processing unit (CPU) is the brain of the computer, carrying out instructions and coordinating hardware components through its arithmetic logic unit, control unit, and memory or storage unit. Computers have evolved through generations, from early vacuum tubes to modern multi-core processors, each improving in speed, efficiency, and usability.

2. WHAT IS A COMPUTER
• A computer is an electronic device that accepts data
from the user, processes it, produces results, displays
them to the users, and stores the results for future
usage.
• Data is a collection of unorganized facts & figures and
does not provide any further information regarding
patterns, context, etc. Hence data means "unstructured
facts and figures".
• Information is a structured data i.e. organized
meaningful and processed data. To process the data
and convert into information, a computer is used.

3. Functions of Computers
Receiving Input
• Data is fed into computer through various input devices like
keyboard, mouse, digital pens, etc. Input can also be fed
through devices like CD-ROM, pen drive, scanner, etc.
Processing the information
• Operations on the input data are carried out based on the
instructions provided in the programs.
Storing the information
• After processing, the information gets stored in the primary
or secondary storage area.
Producing output
• The processed information and other details are
communicated to the outside world through output devices
like monitor, printer, etc.

4. .

5. Input Devices
• Input device enables the user to send data, information, or control
signals to a computer. The Central Processing Unit (CPU) of a
computer receives the input and processes it to produce the
output.
Some of the popular input devices are:
• Keyboard
• Mouse
• Scanner
• Joystick
• Light Pen
• Digitizer
• Microphone
• Magnetic Ink Character Recognition (MICR)
• Optical Character Reader (OCR)
• Digital Camera

6. Central Processing Unit (CPU)
• A Central Processing Unit is also called a processor,
central processor, or microprocessor.
• It carries out all the important functions of a
computer.
• It receives instructions from both the hardware and
active software and produces output accordingly.
• It stores all important programs like operating
systems and application software.
• CPU also helps Input and output devices to
communicate with each other. Owing to these
features of CPU, it is often referred to as the brain of
the computer.

7. Generally, a CPU has three components:
• ALU (Arithmetic Logic Unit)
• Control Unit
• Memory or Storage Unit

8. .
Control Unit: It is the circuitry in the control
unit, which makes use of electrical signals to
instruct the computer system for executing
already stored instructions.
It takes instructions from memory and then
decodes and executes these instructions. So, it
controls and coordinates the functioning of all
parts of the computer.
The Control Unit's main task is to maintain and
regulate the flow of information across the
processor. It does not take part in processing
and storing data.

9. ALU
• It is the arithmetic logic unit, which performs
arithmetic and logical functions.
• Arithmetic functions include addition,
subtraction, multiplication division, and
comparisons.
• Logical functions mainly include selecting,
comparing, and merging the data. A CPU may
contain more than one ALU. Furthermore,
ALUs can be used for maintaining timers that
help run the computer.

10. .
• Memory or Storage Unit/ Registers: It is
called Random access memory (RAM). It
temporarily stores data, programs, and
intermediate and final results of processing.
So, it acts as a temporary storage area that
holds the data temporarily, which is used to
run the computer.

11. TYPES OF MEMORY UNIT

12. ASSIGNMENT
• WRITE SHORT NOTES ON FIVE TYPES OF
MEMORY
• WHAT IS PRIMARY AND SECONDARY MENORY
AND WHAT ARE THEIR COMPONENTS
• DIFFERENCE BETWEEN RAM ROM
• DIFFERNCE BETWEEN CACHE AND RAM
MEMORY

13. Brief history of computer on the basis
Hardware.
First Generation (1940-1956)
• The first generation computers had the following features
and components −
Hardware
• The hardware used in the first generation of computers
was: Vacuum Tubes and Punch Cards.
Features
• It supported machine language.
• It had slow performance
• It occupied large size due to the use of vacuum tubes.
• It had a poor storage capacity.
• It consumed a lot of electricity and generated a lot of heat.

14. Second Generation (1956-1963)
Several advancements in the first-gen computers led to
the development of second generation computers.
Following are various changes in features and
components of second generation computers
Hardware
• Transistors
• Magnetic Tapes
Features
• Batch operating system
• Faster and smaller in size
• Reliable and energy efficient than the previous
generation
• Less costly than the previous generation

15. Third Generation (1964-1971)
Features
• The features of the third generation
computers are −
• Supports time-sharing OS
• Faster, smaller, more reliable and cheaper
than the previous generations
• Easy to access

16. Fourth Generation (1972-2010)
Features
• It supports features like −
• Multiprocessing & distributed OS
• Object-oriented high level programs supported
• Small & easy to use; hand-held computers have
evolved
• No external cooling required & affordable
• This generation saw the development of
networks and the internet
• It saw the development of new trends in GUIs
and mouse

17. Fifth Generation (2010-Present)
Features
• It supports features like −
• Powerful, cheap, reliable and easy to use.
• Portable and faster due to use of parallel
processors and Super Large Scale Integrated
Circuits.
• Rapid software development is possible.

18. Need of hardware and software for
computer
• HARDWARE
• The term hardware refers to mechanical
device that makes up computer. Computer
hardware consists of interconnected
electronic devices that we can use to control
computer’s operation, input and output.
Examples of hardware are CPU, keyboard,
mouse, hard disk, etc.

19. Hardware Components
• Computer hardware is a collection of several
components working together. Some parts are
essential and others are added advantages.
Computer hardware is made up of CPU and
peripherals as shown in image below.
•

20. Different hardware components within
a computer
Computer Hardware Parts
• Some of the commonly used hardware in your
computer are described below:
• Motherboard
• Monitor
• Keyboard
• Mouse

21. Motherboard:
• The motherboard is generally a thin circuit
board that holds together almost all parts of a
computer except input and output devices. All
crucial hardware like CPU, memory, hard
drive, and ports for input and output devices
are located on the motherboard. It is the
biggest circuit board in a computer chassis.
•

22. Components of a Motherboard:
• CPU Slot: It is provided to install the CPU. It is a link between a
microprocessor and a motherboard. It facilitates the use of CPU and
prevents the damage when it is installed or removed. Furthermore,
it is provided with a lock to prevent CPU movement and a heat sink
to dissipate the extra heat.
• RAM Slot: It is a memory slot or socket provided in the
motherboard to insert or install the RAM (Random Access
Memory). There can be two or more memory slots in a computer.
• Expansion Slot: It is also called the bus slot or expansion port. It is a
connection or port on the motherboard, which provides an
installation point to connect a hardware expansion card, for
example, you can purchase a video expansion card and install it into
the expansion slot and then can install a new video card in the
computer. Some of the common expansion slots in a computer are
AGP, AMR, CNR, PCI, etc.

23. .
• Capacitor: It is made of two conductive plates,
and a thin insulator sandwiched between them.
These parts are wrapped in a plastic container.
• Inductor (Coil): It is an electromagnetic coil made
of a conducting wire wrapped around an iron
core. It acts as an inductor or electromagnet to
store magnetic energy.
• Northbridge: It is an integrated circuit that allows
communications between the CPU interface, AGP,
and memory. Furthermore, it also allows the
southbridge chip to communicate with the RAM,
CPU, and graphics controller.

24. • USB Port: It allows you to connect hardware devices
like mouse, keyboard to your computer.
• PCI Slot: It stands for Peripheral Component
Interconnect slot. It allows you to connect the PCI
devices like modems, network hardware, sound, and
video cards.
• AGP Slot: It stands for Accelerated Graphics Port. It
provides the slot to connect graphics cards.
• Heat Sink: It absorbs and disperses the heat generated
in the computer processor.
• Power Connector: It is designed to supply power to the
motherboard.
• CMOS battery: It stands for complementary metal-
oxide-semiconductor. It is a memory that stores the
BIOS settings such as time, date, and hardware
settings.

25. Monitor
• A monitor is the display unit of a computer on which the processed data,
such as text, images, etc., is displayed. It comprises a screen circuity and
the case which encloses this circuity. The monitor is also known as a visual
display unit (VDU).
• Types of Monitors:
• CRT Monitor: It has cathode ray tubes which produce images in the form
of video signals. Its main components are electron gun assembly,
deflection plate assembly, glass envelope, fluorescent screen, and base.
• LCD Monitor: It is a flat panel screen. It uses liquid crystal display
technology to produce images on the screen. Advanced LEDs have thin-
film transistors with capacitors and use active-matrix technology, which
allows pixels to retain their charge.
• LED Monitor: It is an advanced version of an LCD monitor. Unlike an LCD
monitor, which uses cold cathode fluorescent light to backlight the display,
it has LED panels, each of which has lots of LEDs to display the backlight.
• Plasma Monitor: It uses plasma display technology that allows it to
produce high resolutions of up to 1920 X 1080, wide viewing angle, a high
refresh rate, outstanding contrast ration, and more.

26. 3) Keyboard
• A keyboards is an input device through which
users can input text, numbers, and special
characters. It is an input device with a typical
QWERTY keyset.
• It is an external hardware device that is
connected to the computer.
• It serves as the user's most fundamental interface
with a system. It has numerous buttons that can
be used to generate letters, numbers, and
symbols as well as unique keys like the Windows
and Alt keys that can also accomplish other tasks.

27. 4) Mouse:
• It is a small handheld device designed to
control or move the pointer (computer
screen's cursor) in a GUI (graphical user
interface). It allows you to point to or select
objects on a computer's display screen. It is
generally placed on a flat surface as we need
to move it smoothly to control the pointer.
Types of Mouse: Trackball mouse, Mechanical
Mouse, Optical Mouse, Wireless Mouse, etc.

28. What are external hardware
components
• Microphone: A microphone is an input device that converts sound
waves into electrical impulses in order to allow computer-based
audio communications. It was developed by Emile Berliner in 1877.
It is used to enter audio into computers or transform sound waves
into electric waves. It captures audio with the help of converting
sound waves into an electrical signal that could be a digital or
analog signal. This process can be implemented by a computer as
well as other digital audio devices.
•

29. Camera:
• Visual pictures are captured by a camera,
which then transmits them to a computer or a
network device. A camera is a piece of
equipment that takes photographs with the
help of using photosensitive film or a plate
inside of a light-proof housing. The
photosensitive film is exposed to light via the
camera's shutter, which opens and closes as
the image is imprinted onto the film.

33. OUTPUT HARDWARE

35. 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

36. • 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
• An application software is designed for benefit of users to
perform one or more tasks. Examples of application
software include Microsoft Word, Excel, PowerPoint,
Oracle, etc.
QUESTION : DIFFERNCE BETWEEN HARDWARE AND
SOFTWARE

37. .
Sr. Software Hardware
1 It is a collection of programs to bring
computer hardware system into
operation.
It includes physical components of
computer system.
2 It includes numbers, alphabets,
alphanumeric symbols, identifiers,
keywords, etc.
It consists of electronic components
like ICs, diodes, registers, crystals,
boards, insulators, etc.
3 Software products evolve by adding
new features to existing programs to
support hardware.
Hardware design is based on
architectural decisions to make it work
over a range of environmental
conditions and time.
4 It will vary as per computer and its
built-in functions and programming
language.
It is mostly constructed for all types of
computer systems.
5 It is designed and developed by
experienced programmers in high-
level language.
The hardware can understand only
low-level language or machine
language.

38. Different processors used for personal
computers and notebook computers.
What is Processor?
Definition – Processor is known as “Microprocessor“, and
it likes as small type of chip that is placed in the
computers and another electronics components.
Processor can manage all instructions such as
arithmetical, logical, input/output (I/O) and other basic
instructions, which are created by hardware or operating
system.
Its main job role is to obtain input from input devices and
then produce the accurately result on the output devices.

39. Basic Components of Computer
Processor
• ALU stands for arithmetic logic unit, which help
out to execute all arithmetic and logic operations.
• FPU (Floating Point Unit) is also called the “Math
coprocessor” that helps to manipulate
mathematically calculations.
• Registers store all instructions and data, and it
fires operands to ALU and save the output of all
operations.
• Cache memory helps to save more time in
travelling data from main memory.

40. Primary CPU Processor Operations
• Fetch – In which, to obtain all instructions from main
memory unit (RAM).
• Decode – In this operation, to convert all instructions
into understandable ways then other components of
CPU are ready to continue further operations, and this
entire operations ar performed by decoder.
• Execute – Here, to perform all operations and every
components of CPU which are needed to activate to
carry out instructions.
• Write-Back – After executing all operations, then its
result is moved to write back.

41. Types of Processors
Single Core Processor
• Single Core CPUs were used in the traditional type of
computers. Those CPUs were able to perform one
operation at once, so they were not comfortable to
multi tasking system. These CPUs got degrade the
entire performance of computer system while running
multiple programs at same time duration.
• In Single Core CPU, FIFO (First Come First Serve) model
is used, it means that couple of operations goes to CPU
for processing according to priority base, and left
operations get wait until first operation completed.

42. Dual Core Processor
• Dual Core processor contains two processors,
and they are linked with each other like as single
IC (Integrated circuit). Every processor consist its
own local cache and controller, so they are able
to perform different difficult operations in quickly
than single core CPU.
• There are some examples which are used as dual
core processors such as Intel Core Duo,
the AMD X2, and the dual-core PowerPC G5.

43. Multi Core Processor
• Multi core processor is designed with using of
various processing units means “Cores” on
one chip, and every core of processor is able
to perform their all tasks. For example, if you
are doing multiple activities at a same time
like as using WhatsApp and playing games
then one core handles WhatsApp activities
and other core manage to another works such
as game.

44. Quad Core Processor
• Quad core processor is high power CPU, in which
four different processors cores are combined into
one processor. Every processor is capable to
execute and process all instructions own level
without taking support to other left processor
cores. Quad core processors are able to execute
massive instructions at a time without getting
waiting pools. Quad core CPU help to enhance
the processing power of computer system, but it
performance depend on their using computing
components.

45. Octa Core Processor
• Octa core processor is designed with using of
multiprocessor architecture, and its design
produces the higher processing speed. Octa
core processor has best ability to perform
multi tasking and to boost up efficiency of
your CPU. These types of processors are
mostly used in your smart phones.