Computers can be categorized by size and performance. Personal computers like desktops and laptops are microcomputers commonly used by individuals. Larger systems include minicomputers and mainframes used by large organizations. A computer contains a processor, memory, storage, input/output devices, and software. It executes programs to perform tasks like banking, weather forecasting, and medical diagnosis. Hardware components communicate via the motherboard and work together under the instruction of software.

2. What is a computer?
A computer is an electronic
device that executes the
instructions in a program.

3. Benefits of Computers
The three main benefits of using computers are :
Speed
Accuracy
Capacity to take large amount of work.

4. Applications
Computers are used in various fields ranging from
making cartoon films to
space research.
Some applications of computers are:
Railway reservation
Banking and Accounts
Weather Forecast
Space Research
Weather Forecast
Space Research
Medical Diagnosis
Chemical Analysis

5. Types of computers
Computers are categorized on the basis of size, sot
and performance.
Generally, the larger the system, the greater is its
processing speed, storage capacity, cost and ability to
handle large number of devices. The various types of
computers are:
Microcomputer
Personal computers/laptops
Minicomputers
Mainframes
Super computers

6. Microcomputers
Systems on the lower end of the size of the size
scale are microcomputers.
They may be tiny special purpose devices
dedicated to carrying out a single task such as one
inside a camera.

7. Personal Computers
The most popular form of computer in use today
is the Personal Computer generally known as the
PC.
The PC can be used for various application.
It can be defined as a single user oriented and
general purpose microcomputer.

8. Lap Top
Lately, the Palmtops and Laptops have
become very popular with their power and
portability.
It can perform a diverse range of
functions, from keeping track of household
accounts to keeping records of the stores
of a large manufacturing company.

9. Mini Computers
Mini computers are small, general-purpose
computers.
They can vary in size from a small desktop model
to the size of a small filing cabinet.
A typical mini system is more expensive than a PC
and surpasses of PC in storage capacity and speed.

10. contd………
While most PCs are oriented towards single
users,minisystems are designed to handle the needs of
multiple users, i.e., more than one person can work on
a mini at the same time.

11. Mainframes
A mainframe is another form of
a computer system that is
generally more
powerful than a typical mini.
Mainframes themselves may
vary widely in cost
and capability. They are used in
large organizations for large
scale jobs.
However, there is an overlap
between the expensive minis
and small
mainframe models in terms of
cost and capability.

12. Super computers
At the end of the size and capability scale,
are the super computers.
These systems are the largest, fastest and
most expensive computers in the world.
These computers are owned by large
organizations.
They are used for complex scientific
applications.

14. Software
Software is a computer
program that is made up of
certain instructions or
codes that tell your
hardware, or computer,
what to do.
Software can be used to
play games, write school
papers, or even sort e-mail

15. Hardware
The physical parts of the computer that you can
actually touch
Camera
Monitor
Scanner
Computer
Microphone Mouse
Keyboard

16. components
motherboard Input/output
devices
processor
keyboard
Bios/cmos
mouse
chipset
monitor
Real time
clock chip camera
speakers

17. ROM
Primary storage
RAM
DVD drive
Secondary storage Hard disk
Floppy disk

18. processor
Processor is the brain of the computer.
It deals Data processing & execution of data's is
perform in it.
It does all the thinking for the computer and process
all the information to be turned into files on your
computer.

19. BIOS(Basic input output
system)
The Basic Input/output
System controls the
computer’s basic
operations and is
responsible for
starting up the
computer and
hardware.
Its most important
role is to load the
operating system.

20. Some of the other common tasks that the BIOS
performs include:
Check the CMOS Setup for custom settings
Load the interrupt handlers and device drivers
Initialize registers and power management
Perform the power-on self-test (POST)
Display system settings
Determine which devices are bootable

21. CMOS Battery
The system BIOS and the
information required to
configure it is stored on a
Complementary Metal-
Oxide Semiconductor
(CMOS) chip.
CMOS is a battery-powered
storage chip located on the
system board.
The CMOS chip has
rewritable memory since
the configuration data can
be changed or updated as
the components or devices
in the computer are
changed.

22. Real time clock chip:
The RTC is essentially a
quartz watch that runs
all the time, whether or
not the computer has
power.
The battery powers this
clock.
RTC gets the correct
time and date when
system is booted.

23. Chipset: The chipset is the
"glue" that connects
the microprocessor
to the rest of the
computer.
It consists of two
basic parts -- the
Northbridge and the
Southbridge.

24. Input/ output devices
A keyboard is used mainly for
typing text into your computer.
Like the keyboard on a
typewriter, it has keys for
letters and numbers, but it also
has special keys.

25. Mouse A mouse is a small device
used to point to and select
items on your computer
screen. Allows the entry of
data and executes
programs.

26. MONITERS
A monitor displays information in visual form, using
text and graphics.
The portion of the monitor that displays the
information is called the screen.
Like a television screen, a computer screen can show
still or moving pictures.
There are two basic types of monitors: CRT (cathode
ray tube) monitors and the newer LCD (liquid crystal
display) monitors.

27. CRT (cathode ray
tube) monitors
LCD (liquid crystal display)
monitors.

28. web camera
A webcam is a video camera that
feeds its images in real time to
a computer or computer network.
The common use as a video
camera for the World Wide
Web gave the webcam its name
Webcams are known for their
low manufacturing cost and
flexibility, making them the lowest
cost form of videotelephony.

29. speakers
Computer speakers,
or multimedia speakers,
are speakers external to a
computer, that disable the
lower fidelity built-in
speaker.
The computer speakers
typically packaged with
computer systems are
small, plastic, and have
mediocre sound quality.
Laptops has integrated
sound devices.
It deals with low sound
quality.

30. STORAGES
Primary storages consists of two types.
They are
ROM(Read only memory)
RAM(Random access memory)

31. ROM
Computers almost always contain a small amount of
read-only memory that holds instructions for starting
up the computer. Unlike RAM, ROM cannot be written
to.
Types of ROM
PROM(programmable read-only memory):
EPROM (erasable programmable read-only memory)
EEPROM (electrically erasable programmable read-
only memory):

32. RAM
Primary storage for cpu
Integrated services are
used to temporarily store
programs, instructions
and data.
It is a volatile memory
Types of ram:
SD(Synchronous dynamic
random-access memory)
DDR1 (Double data rate
RAM1 )
DDR2 (Double data rate
RAM2)
DDR3 (Double data rate
RAM3)

34. Secondary storages
There are three types of secondary devices
They are
Dvd drive
Hard disk
Floppy disk

35. CD and DVD drive
Nearly all computers today come equipped with a CD or
DVD drive, usually located on the front of the system
unit.
CD drives use lasers to read (retrieve) data from a CD;
many CD drives can also write (record) data onto CDs.

36. HARDDISK
storage device that holds the operating
system and other programs and data files.

37. Floppy disk
Perhaps the slowest form of long
term secondary storage for the
computer is the floppy disk with
1.44 MB disk drive.

38. MOTHERBOARD
This transfers data between all of the computer’s
components: the human nervous system.
It is the main circuit board that incommoded
processor slot, RAM slot , Extension slot , PCI
slot, Serial port, parallel port, connectors for
keyboard & mouse etc.