Computer Hardware and Software
August 21 – August 25
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Introduction to Information Technology:
o
Information technology (IT) is any computer-based tool that people use to work
with information and support the information and information-processing needs
of an organization (p. 39).

IT extends beyond the computer, but to many other tools that help you
use information more effectively. A printer, for example, helps you use
information by creating a “hard” paper copy. A local area network
allows people to share information around the world. A cell phone
allows you to communicate and even connect to the Internet. Software
such as Microsoft Word can help you create letters and memos.
o
IT tools can be broken down into two broad categories: hardware and software
(p. 40).

Hardware is the physical devices that make up a computer.

Software is the set of instructions that your hardware executes to carry
out a specific task for you. Software is the “go-between” that allows you
to use the hardware.

Binary:
o
A binary digit (bit) is the smallest unit of information that your computer can
process (p. 51).
o
A bit can either be “on” or “off”. Numerically, an “on” bit is represented by a 1
and an “off” bit is represented by a 0 (p. 51).
o
Physically, an “on” bit is typically represented by one electrical voltage and
“off” bit is typically represented by a different electrical voltage.
o
These bits are formed into a series of eight bits, known as bytes. One byte
represents one character (p. 51).

o
For example, c is represented by the following byte: 01100011.
Computer storage is represented by the following terminology:

1 megabyte (MB) = 1 million bytes (1 million characters)

1 gigabyte (GB) = 1 billion bytes (1 billion characters)

1 terabyte (TB) = 1 trillion bytes (1 trillion characters)
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Hardware:
o Hardware can be broken down into six categories (p. 41).
o

Input device

Output device
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Storage device
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Central processing unit (CPU)
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Telecommunications device

Connecting devices
An input device is a tool that you use to provide information and commands.

Examples include the keyboard, microphone, mouse, scanner, point-ofsale (POS), etc. (pp. 52-53).
o
An output device is a tool that allows you to see or hear the results of your
information processing requests.

o
Examples include monitors, printers, and speakers (pp. 54-56).
A storage device is a tool that allows you to store information for use at a later
time (pp. 56-58).
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These storage devices are permanent.

These storage devices are usually either magnetic surfaces or surfaces
that reflect light (a.k.a. optical).

These devices are usually quite slow.

Common storage devices include:
Device
Floppy disk
Hard disk drive
CD-ROM drive
DVD-ROM drive
o
Type
Magnetic
Magnetic
Optical
Optical
Size
1.44 MB
Up to 100 GB
650-800 MB
4.2-17 GB
The central processing unit (CPU) is the actual hardware that interprets and
executes the software instructions and coordinates how all the other hardware
devices work together (p. 59).

Basically, the CPU is the “brain” of the computer.

The CPU works closely with random access memory (RAM).

RAM is temporary storage that stores data that the CPU is about to use.
RAM is quick and electrical (p. 59).
o
A telecommunications device is a tool you use to send information to and receive
it from another person or location.

o
The common telecommunications device is the modem (p. 41).
Connecting devices enable hardware devices, particularly those outside the
computer, with the computer (pp. 61-63).

Software:
o
o
There are two main types of software: application and system (p. 45).
Application software is the software you use to meet specific informationprocessing needs. Examples include Microsoft Word, Internet Explorer, and
Adobe Photoshop, etc. (p. 45).

Application software is broken into two categories: personal productivity
software and vertical and horizontal market software.

Personal productivity software is used to help individuals and
includes things like word processing or photo editing (p. 45).

Vertical and horizontal market software is used to help entire
companies, and includes things like inventory management
software (pp. 46-47)
o
System software is the category of software that controls how your various
hardware devices work together as you use your application software to perform
specific information-processing tasks (p. 42).

The most popular type of system software is the operating system. The
operating system controls your application software and manages your
hardware (p. 42).

Utility software adds functionality to the OS. Examples include antivirus
software, backup software, disk optimization software, etc (p. 42).