2. Contents
• What is Computer?
• Who is a User?
• Data & Information
• InformationTechnology (IT)
• History of Computers
• Generations
• Types of Computers
• Classification of Computers
3. What is Computer?
Definitions:
• A computer is normally considered as calculating machine
that can perform arithmetic operation at a very high speed.
• Computers are electronic devices that is programmed to
• accept data ( input ),
• ( process ) that data into useful information,
• produce ( output ), and then
• ( store ) for later use.
4. Who is a user?
• Someone that communicates with a computer
5. Data & Information
Definitions:
• DATA
A collection of raw facts and figures is called data.
It may consist of numbers, characters, symbols etc
• INFORMATION
Processed data is called information.
It is more meaningful than data.
6. InformationTechnology
• Information is data that is organized,
meaningful, and useful.
• Information technology is the use of systems
(especially computers and telecommunications)
for storing, retrieving, and sending information..
• Computer is a very important component of
information technology
10. First Generation -VacuumTubes
1. From 1946 to 1956
• It can perform 2,000 to 16,000
additions per second
• Had main memory 100 bytes
to 2 kilobytes
2. Used vacuum tubes
3.Very large machines
• special rooms to house them
with air conditioning
• specially trained technicians to
run & maintain
11. Second Generation -Transistors
1. From 1959 to around 1965
2. Smaller, faster, and more reliable
used transistors
6,000 to 3,00,000 operations/s
main memory 6 kilobytes to 1.3 megabytes
3. one-tenth the price of a 1 Generation
4. become common in larger businesses
and universities
st
12. Third Generation - Integrated Circuits
1. Form 1965 to around 1972
2. Used integrated circuits – many
transistors on one piece of silicon
3. Smaller, faster, more reliable, and lower
in price
• Size of a stove or refrigerator, some can fit
on desktops
• Can do 100,000 to 400,000,000 operations
per second
• Cost about one-tenth the amount of second
generation computers
4.These Computers become very common
in medium to large businesses
13. Fourth Generation - Microprocessors
1. From 1972 until now
2. Used large scale to very large scale integrated circuits
• Put more than one IC on a silicon chip
• Can do more than one function
3. smaller, faster, more reliable, and lower in price
• Size of a television or much smaller
• Can do 500,000 to 1,000,000,000 operations/second
• Cost one-tenth, or less, the amount of third generation
4. very common in homes and business
15. Analog Computers
• An analog computer recognizes data as a
continuous measurement of a physical property.
• It has no state
• Its output is usually displayed on a meter or graphs.
• Examples are Analog clock, speedo-meter of a car,
thermo-meter etc
16. Digital Computers
• It works with numbers
• They breaks all types of information into tiny units and use
numbers to represent those pieces of information.
• Everything is described in two states i.e. either ON (1) orOFF
(0).
• They are very fast and have big memory
19. Supercomputer
• A supercomputer is a computer with a high-level computational
capacity compared to a general-purpose computer .
• It comprised of multiple high performance computers working in
parallel as a single system.
• Super Computers uses thousands of processor at a same time.
• Used for nuclear weapon weather forecasting , Scientific
Simulition , oil and gas exploration or in large companies.
20. Mainframe
• Mainframes are huge computers
that could fill an entire room or
even a whole floor!
• mainframes can run multiple
instances of operating systems at
the same time.
• Mainframe are used primarily by
large organizations for critical
applications, bulk data processing
• It uses for online data storage.
• Mainframe used for transaction
processing in banking, Airlines etc
21. Workstation
• A desktop computer that has a more powerful
processor,
• additional memory (RAM, Hard drive) and
enhanced capabilities for performing a special
group of task, such as 3D Graphics or game
development.
• Multiple users can use single workstation all
together.
22. Server
• A computer that has been optimized to provide
services to other computers over a network.
• Servers usually have powerful processors, lots of
memory and large hard drives.
• Multiple CPU ’s & Hard drives
23. DESKTOP
• A PC that is not designed for portability.
• you will set the computer up in a permanent location.
• Most desktops offer more power, storage and
versatility for less cost than portable computers.
24. Laptop
• Also called notebooks .
• Laptop are portable computers that integrate
the display, keyboard, a pointing device or
trackball, processor, memory and hard drive
all in a battery-operated package.
25. Palmtop
• More commonly known as Personal
Digital Assistants (PDAs)
• palmtops are tightly integrated
computers that often use flash memory
instead of a hard drive for storage.
• usually do not have keyboards but rely
on touchscreen technology for user
input.
• A slightly larger and heavier version of
the palmtop is the handheld
computer .