 What is a
Computer?
Computers are not
very intelligent devices, but they handle instructions flawlessly and fast.
Computers cannot really think for themselves (yet.) They
must follow explicit instructions from both the user, in the form of input or
commands, and computer programmer, in the form of software.
Computers are really nothing more than a very powerful calculator with some
great accessories. Applications like word processing and games are just a very
complex math problem.
Software and
Hardware
If you use a
player piano as an analogy, the piano can be thought of as the hardware and the
roll of music as the software.
The software a series of very simple computer instructions carefully organized
to complete complex tasks. These instructions are written in programming
languages (like BASIC, PASCAL, C...) to help simplify the development of
applications.
The hardware is what sits on your desk and executes the software instructions.
The player piano is useless unless the roll of music has been written correctly.
Hardware
Components
Input Devices - "How to tell it what to do"
A keyboard
and mouse are the standard way to interact with the computer. Other devices
include joysticks and game pads used primarily for games. Modern
computers also have microphones for speech recognition programs, recording words
or sound clips, as well as voice over internet (VoIP) phone calls
Output Devices - "How it shows you what it is doing"
The monitor
(the screen) is how the computer sends information back to you, whether it
be surfing the web or writing a memo. A printer is also an output device.
Speakers are also an output device, so yo can get audible cues from the
operating system, and also for listening to music, sound from videos, or on-line
newscasts.
Storage Devices - "How it saves data and programs"
 Hard disk
drives are an internal, higher capacity drive which also stores the
operating system which runs when you power on the computer.
"Floppy" disk drives allow
you to save work on small disks and take the data with you.
CD and DVD drives allow you to write to an optical storage disc, or "burn" a CD
or DVD.
USB Key Drives, Flash Drives, or Thumb Drives allow you to save data through the
Universal Serial Bus port, and come in storage capacities from 128MB to 5GB
Memory - "How the processor stores and uses immediate data"
When you
use a program, the computer loads a portion of the program from the hard
drive to the much faster memory (RAM). When you "save" your work or quit the
program, the data gets written back to the hard drive.
Microprocessors - "The brain of the computer"
 PCs primarily use microprocessors (sometimes called the chip) manufactured
by Intel. The older Intel versions include the 386, 486 and now the Pentium
I, II, III, and IV
lines.
Macintoshes
use PowerPC processors by Motorola.
Megahertz
(MHz) is the internal processor speed in which computer instructions are
performed. The MHz speed does not always indicate the power of the
microprocessor. Newer processors can execute more instructions at the same
or slower MHz. For example, an Intel 486 @100MHz is less powerful
than a Pentium @75 MHz (but the MHz is "faster").
We will be covering hardware in more detail in the next segment.
Operating System
Software
Operating system
software provides a "user interface" for users to manage files, start programs,
customize computer settings, and other tasks. The operating system also provides
the fundamental core computer functionality for programmers. A computer
will not run unless there is an operating system installed
-
Intel
x86 based PCs use Microsoft Windows XP Home or XP Professional as the
operating system. Windows runs about 97% of the desk top computers
worldwide, and about 60% of server systems.
-
Apples use the Macintosh Tiger OS X operating system.
-
Other operating systems include Unix, Linux, Novell, DOS, HP-UX.
We will be covering the operating system in greater detail later.
Software
Applications
Application
software uses the operating system software and provides the real functionality
of a computer. Applications include:
-
Internet Browsers (Netscape Navigator, MS Internet Explorer)
-
E-Mail Applications (Outlook Express, Outlook, etc)
-
Word Processing (MS Word, WordPerfect)
-
Spreadsheets (MS Excel...)
-
Database (MS
Access, DBase, Fox Pro, Oracle...)
-
Presentation (MS PowerPoint, Persuasion...)
-
Games
We will cover many of these application in Day Two of our class.
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Special thanks to
the Bedford Public Library for the material on this page | 
