Introduction To Computer Science

1. Basic Computer

2. What is Computer
• A computer is not an acronym and sometimes abbreviated as comp or 'puter. The term
"computer" was originally given to humans who performed numerical calculations using
mechanical calculators, such as the abacus and slide rule. The term was later given to a
mechanical device as they began replacing the human computers. Today's computers are
electronic devices that accept data (input), process that data, produce output, and then
store (storage) the results.
• Computer is an electronic device that is designed to work with Information. The term
computer is derived from the Latin term ‘computare’, this means to calculate. Computer
can not do anything without a Program.it represents the decimal numbers through a
string of binary digits. The Word 'Computer‘ usually refers to the Center Processor Unit
plus Internal memory.

3. Types of Computer
• Desktop computers
Desktop computers are designed for
use at a desk or table. They are
typically larger and more powerful
than other types of personal computers.
Desktop computers are made up of
separate components. The main
component, called the system unit, is
usually a rectangular case that sits on
or underneath a desk. Other
components, such as the monitor,
mouse, and keyboard, connect to the
system unit.

4. Types of Computer
Laptops and netbooks
• Laptops are lightweight mobile PCs with a
thin screen. Laptops can operate on
batteries, so you can take them anywhere.
Unlike desktops, laptops combine the
CPU, screen, and keyboard in a single
case. The screen folds down onto the
keyboard when not in use.
• Netbooks (also referred to as mini
notebooks), are small, affordable laptops
that are designed to perform a limited
number of tasks. They're usually less
powerful than laptops, so they're used
mainly to browse the web and check
e-mail.

5. Types of Computer
Smartphones
• Smartphones are mobile phones that have
some of the same capabilities as a computer.
You can use a smartphone to make telephone
calls, access the Internet, organize contact
information, send e-mail and text messages,
play games, and take pictures. Smartphones
usually have a keyboard and a large screen.

6. Types of Computer
Handheld computers
• Handheld computers, also called personal
digital assistants (PDAs), are battery-powered
computers small enough to carry almost
anywhere. Although not as powerful as
desktops or laptops, handheld computers are
useful for scheduling appointments, storing
addresses and phone numbers, and playing
games. Some have more advanced
capabilities, such as making telephone calls or
accessing the Internet. Instead of keyboards,
handheld computers have touch screens that
you use with your finger or a stylus (a pen-
shaped pointing tool).

7. Types of Computer
Tablet PCs
• Tablet PCs are mobile PCs that combine
features of laptops and handheld computers.
Like laptops, they're powerful and have a
built-in screen. Like handheld computers,
they allow you to write notes or draw
pictures on the screen, usually with a tablet
pen instead of a stylus. They can also convert
your handwriting into typed text. Some
Tablet PCs are “convertibles” with a screen
that swivels and unfolds to reveal a keyboard
underneath.

8. Types of Computer
Super Computers
• The most powerful computers in terms of
performance and data processing are the
supercomputers. These are specialized and task
specific computers used by large organizations. These
computers are used for research and exploration
purposes, like NASA uses supercomputers for
launching space shuttles, controlling them and for
space exploration purpose.
• The supercomputers are very expensive and very
large in size. It can be accommodated in large air-
conditioned rooms; some super computers can span
an entire building. “In 1964, Seymour cray designed
the first supercomputer CDC 6600”

9. Types of Computer
Uses of Supercomputer
• In Pakistan and other countries Supercomputers are used by Educational Institutes like
NUST (Pakistan) for research purposes. Pakistan Atomic Energy commission & Heavy
Industry Taxila uses supercomputers for Research purposes.
Space Exploration
• Supercomputers are used to study the origin of the universe, the dark-matters. For these
studies scientist use IBM’s powerful supercomputer “Roadrunner” at National Laboratory
Los Alamos.
Earthquake studies
• Supercomputers are used to study the Earthquakes phenomenon. Besides that
supercomputers are used for natural resources exploration, like natural gas, petroleum,
coal, etc.

10. Types of Computer
Uses of Supercomputer (Cont)
Weather Forecasting
• Supercomputers are used for weather forecasting, and to study the nature and extent of
Hurricanes, Rainfalls, windstorms, etc.
Nuclear weapons testing
• Supercomputers are used to run weapon simulation that can test the Range, accuracy & impact of
Nuclear weapons.
Popular Supercomputers
• IBM’s Sequoia, in United States
• Fujitsu’s K Computer in Japan
• IBM’s Mira in United States
• IBM’s SuperMUC in Germany
• NUDT Tianhe-1A in China

11. Types of Computer
Servers Computers
• Servers are a step under supercomputers, because they
don't focus on trying to solve one very complex problem,
but try to solve many similar smaller ones. An example of
a server would be the computers that Wikipedia stores its
encyclopedia on. Those computers have to go and find the
page you're looking for and send it to you. In itself it's not
a big task, but it becomes a job for a server when the
computers have to go and find lots of pages for a lot of
people and send them to the right place. Some servers, like
the ones Google uses for something like Google
Documents, have applications on them instead of just
files, like Wikipedia.
• A server is a central computer that contains collections of
data and programs. Also called a network server, this
system allows all connected users to share and store
electronic data and applications. Two important types of
servers are file servers and application servers.

12. Types of Computer
Mainframe computer
• Although Mainframes are not as powerful as
supercomputers, but certainly they are quite
expensive nonetheless, and many large firms &
government organizations uses Mainframes to run
their business operations. The Mainframe computers
can be accommodated in large air-conditioned
rooms because of its size. Super-computers are the
fastest computers with large data storage capacity,
Mainframes can also process & store large amount
of data. Banks educational institutions & insurance
companies use mainframe computers to store data
about their customers, students & insurance policy
holders.
Fujitsu’s ICL VME
Hitachi’s Z800

13. Types of Computer
Game consoles
A game console is a specialized kind of
computer that is used for playing video games.
Although they are not as fully featured as
desktop computers, many newer consoles, such
as the Nintendo Wii & PS3,4, allow you to
perform nongaming tasks like browsing the
Web.