Computer Hardware and Software
January 9 – January 13

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

Storage device

Central processing unit (CPU)

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-of-sale
(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.
52-53).

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. 58).
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. 60).
Connecting devices enable hardware devices, particularly those outside the computer,
with the computer.

Software:
o
o
There are two main types of software: application and system (p. 43).
Application software is the software you use to meet specific information-processing
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).