Computers
How they work and what we can do with them
Why Use Computers?

What do we use computers for each day?
Computer Definition

Any electronic machine that stores, processes and
retrieves information.

One of the most useful and widespread technology
tools.

Computers have different capabilities

Some are slower/faster, smaller/larger
Computer Units
Unit
Number of Bytes
Kilobyte (KB)
1,024
Megabyte (MB)
1,024,000
Gigabyte (GB)
1,024,000,000
Terabyte (TB)
1,024,000,000,000
Used to determine file size or storage capacity
Types of Computers

Microcomputers: extremely small, built into electronics
(games, ATMs, cars, phones)

Personal Computer (PC): general purpose, single user
computer.

Mainframe Computer: Large computer used by
organizations with many computers that work with large
amounts of data.

Supercomputer: Fastest and largest used today. Used
for research and analyzing huge amounts of data –
trillions per second (weather forecasting, climate
research, oil exploration, quantum mechanics, etc.)
What runs a computer?

The operating system tells your computer what to do.
It coordinates communication between programs,
hardware, and other applications.

Examples:

Windows 7 – what we use here at school

OS X Lion (for MAC)
4 Functions of Computers
Input
Processing
Output
Storage
Input

Everything we tell the computer

Data or facts

Commands (“open”, “save”)

Responses (answers to computer’s questions “Are you
sure you want to delete this document?”)

Input devices: keyboard, scanner, CD’s, webcam,
numeric keypad, etc.)
Processing

The thinking a computer does (calculations,
comparisons, decisions)

All computers have CPUs (Central Processing Units)

CPU = brains of the computer, small microchip that gets
extremely hot which is why the computers have fans
inside
Output

Data that is processed into useful form, now called
information (printed papers, information displayed on
screen, power points, charts, videos, etc.)
Storage

Ways computers keep information so it’s available for
future use

On the hard drive

RAM (Random Access Memory) The more RAM a computer
has, the more storage space it has
You can also store information on external sources like a flash
drive (jump drive, thumb drive) or CD-ROM. We can also
save on the network J drive.
How your computer thinks
Computer Parts
Computer Parts
CPU
Computer Parts
Hardware vs. Software

Hardware is the physical components of the computer
(processor, memory, monitor, etc.)

Software tells a computer what to do

2 Types:

Operating System (Windows 7)

Application Program (Word, Power Point, games)
Computer Virus

A software program that attaches itself to other
programs

Alter or delete files

Consume computer memory

NEVER go on the internet without having updated antivirus
software installed on your computer.
Computer Virus
Internet

A worldwide network of millions of private, public,
academic, business, and government networks

Began in late 1960s by the Pentagon

WWW = World Wide Web
How the Internet works
Social Networking
Obsessed with Facebook

1.49 billion monthly active Facebook users (2015)

968 million daily users (2015)

83% of those users live outside the U.S. (2015)

Social networking is the most rapidly growing area of the
internet
Twitter is Gaining

316 million monthly active users (2015)

100 million active daily users (2015)

40% of users only follow others, don’t tweet
The Future?

We are moving towards cloud computing

Computers may become nothing more
than an internet portal

More online sharing, collaboration, and creating
Evolution of Computers

3000 B.C. Abacus is invented in Babylonia

600 A.D. Arabic numbers and the concept of zero are
invented in India
Evolution of Computers

1623 Wilhelm Schickard builds first mechanical
calculator

1844 Samuel Morse sends first telegraph message from
Washington to Baltimore
Evolution of Computers

1895 Guglielmo Marconi transmits first radio signal

1927 First demonstration of television in the United
States

1939 prototype of an electronic digital computer is built
Evolution of Computers

1947 Bell labs develops the first transistor (fundamental
building block of modern electronics)

1953 The IBM 650 becomes the first mass produced
computer (filled an entire room)

1960 First computer with keyboard and monitor input
(mouse invented in 1964)
Evolution of Computers

1973 The “office computer” is developed by Alan Kay

1977 Steve Jobs and Steve Wozniak build Apple II and
establish benchmark for personal computers
Evolution of Computers

1977 Bill Gates and Paul Allen found Microsoft

1983 Creation of the global internet

1984 CD-ROM developed

2010 76.7% of households have a computer
Evolution of Computers

1993 internet carries 1% of information flowing through
two-way telecommunication

2000: 51%

2007: 97%

2004 Facebook launched

2008 Laptops out sell desktops