the Physical Computer
a Training Module of the
Assistive Technology Division
Mississippi Department of Rehabilitation Services
Note: Computer terms and filename extensions are copyrighted by Saugus.net; used with permission.
Glossary
application & app
An application (often called "app" for short) is simply a program
with a GUI. Note that it is different from an applet.
boot
Starting up an OS is booting it. If the computer is already running, it is more
often called rebooting.
browser
A browser is a program used to browse the web. Some common browsers include
Netscape, MSIE (Microsoft Internet Explorer), Safari, Lynx, Mosaic, Amaya, Arena,
Chimera, Opera, Cyberdog, HotJava, etc.
bug
A bug is a mistake in the design of something, especially software. A really
severe bug can cause something to crash.
chat
Chatting is like e-mail, only it is done instantaneously and can directly involve
multiple people at once. While e-mail now relies on one more or less standard
protocol, chatting still has a couple competing ones. Of particular note are
IRC and Instant Messenger. One step beyond chatting is called MUDding.
click
To press a mouse button. When done twice in rapid succession, it is referred
to as a double-click.
cursor
A point of attention on the computer screen, often marked with a flashing line
or block. Text typed into the computer will usually appear at the cursor.
database
A database is a collection of data, typically organized to make common retrievals
easy and efficient. Some common database programs include Oracle, Sybase, Postgres,
Informix, Filemaker, Adabas, etc.
desktop
A desktop system is a computer designed to sit in one position on a desk somewhere
and not move around. Most general purpose computers are desktop systems. Calling
a system a desktop implies nothing about its platform. The fastest desktop system
at any given time is typically either an Alpha or PowerPC based system, but
the SPARC and PA-RISC based systems are also often in the running. Industrial
strength desktops are typically called workstations.
directory
Also called "folder", a directory is a collection of files typically
created for organizational purposes. Note that a directory is itself a file,
so a directory can generally contain other directories. It differs in this way
from a partition.
disk
A disk is a physical object used for storing data. It will not forget its data
when it loses power. It is always used in conjunction with a disk drive. Some
disks can be removed from their drives, some cannot. Generally it is possible
to write new information to a disk in addition to reading data from it, but
this is not always the case.
drive
A device for storing and/or retrieving data. Some drives (such as disk
drives, zip drives, and tape drives) are typically capable of having new data
written to them, but some others (like CD-ROMs or DVD-ROMs) are not. Some drives
have random access (like disk drives, zip drives, CD-ROMs, and DVD-ROMs), while
others only have sequential access (like tape drives).
e-mail
E-mail is short for electronic mail. It allows for the transfer of information
from one computer to another, provided that they are hooked up via some sort
of network (often the Internet. E-mail works similarly to FAXing, but its contents
typically get printed out on the other end only on demand, not immediately and
automatically as with FAX. A machine receiving e-mail will also not reject other
incoming mail messages as a busy FAX machine will; rather they will instead
be queued up to be received after the current batch has been completed. E-mail
is only seven-bit clean, meaning that you should not expect anything other than
ASCII data to go through uncorrupted without prior conversion via something
like uucode or bcode. Some mailers will do some conversion automatically, but
unless you know your mailer is one of them, you may want to do the encoding
manually.
file
A file is a unit of (usually named) information stored on a computer.
firmware
Sort of in-between hardware and software, firmware consists of modifiable programs
embedded in hardware. Firmware updates should be treated with care since they
can literally destroy the underlying hardare if done improperly. There are also
cases where neglecting to apply a firmware update can destroy the underlying
hardware, so user beware.
floppy
An extremely common type of removable disk. Floppies do not hold too much data,
but most computers are capable of reading them. Note though that there are different
competing format used for floppies, so that a floppy written by one type of
computer might not directly work on another. Also sometimes called "diskette".
format
The manner in which data is stored; its organization. For example, VHS, SVHS,
and Beta are three different formats of video tape. They are not 100% compatible
with each other, but information can be transferred from one to the other with
the proper equipment (but not always without loss; SVHS contains more information
than either of the other two). Computer information can be stored in literally
hundreds of different formats, and can represent text, sounds, graphics, animations,
etc. Computer information can be exchanged via different computer types provided
both computers can interpret the format used.
function keys
On a computer keyboard, the keys that start with an "F" that are usually
(but not always) found on the top row. They are meant to perform user-defined
tasks.
graphics
Anything visually displayed on a computer that is not text.
hardware
The physical portion of the computer.
hypertext
A hypertext document is like a text document with the ability to contain pointers
to other regions of (possibly other) hypertext documents.
Internet
The Internet is the world-wide network of computers. There is only one Internet,
and thus it is typically capitalized (although it is sometimes referred to as
"the 'net"). It is different from an intranet.
keyboard
A keyboard on a computer is almost identical to a keyboard on a typewriter.
Computer keyboards will typically have extra keys, however. Some of these keys
(common examples include Control, Alt, and Meta) are meant to be used in conjunction
with other keys just like shift on a regular typewriter. Other keys (common
examples include Insert, Delete, Home, End, Help, function keys,etc.) are meant
to be used independently and often perform editing tasks. Keyboards on different
platforms will often look slightly different and have somewhat different collections
of keys. Some keyboards even have independent shift lock and caps lock keys.
Smaller keyboards with only math-related keys are typically called "keypads".
language
Computer programs can be written in a variety of different languages. Different
languages are optimized for different tasks. Common languages include Java,
C, C++, ForTran, Pascal, Lisp, and BASIC. Some people classify languages into
two categories, higher-level and lower-level. These people would consider assembly
language and machine language lower-level languages and all other languages
higher-level. In general, higher-level languages can be either interpreted or
compiled; many languages allow both, but some are restricted to one or the other.
Many people do not consider machine language and assembly language at all when
talking about programming languages.
laptop
A laptop is any computer designed to do pretty much anything a desktop system
can do but run for a short time (usually two to five hours) on batteries. They
are designed to be carried around but are not particularly convenient to carry
around. They are significantly more expensive than desktop systems and have
far worse battery life than PDAs. Calling a system a laptop implies nothing
about its platform. By far the fastest laptops are the PowerPC based Macintoshes.
memory
Computer memory is used to temporarily store data. In reality, computer memory
is only capable of remembering sequences of zeros and ones, but by utilizing
the binary number system it is possible to produce arbitrary rational numbers
and through clever formatting all manner of representations of pictures, sounds,
and animations. The most common types of memory are RAM, ROM, and flash.
modem
A modem allows two computers to communicate over ordinary phone lines. It derives
its name from modulate / demodulate, the process by which it converts digital
computer data back and forth for use with an analog phone line.
monitor
The screen for viewing computer information is called a monitor.
mouse
In computer parlance a mouse can be both the physical object moved around to
control a pointer on the screen, and the pointer itself. Unlike the animal,
the proper plural of computer mouse is "mouses".
multimedia
This originally indicated a capability to work with and integrate various types
of things including audio, still graphics, and especially video. Now it is more
of a marketing term and has little real meaning. Historically the Amiga was
the first multimedia machine. Today in addition to AmigaOS, IRIX and Solaris
are popular choices for high-end multimedia work.
NC
The term network computer refers to any (usually desktop) computer system that
is designed to work as part of a network rather than as a stand-alone machine.
This saves money on hardware, software, and maintenance by taking advantage
of facilities already available on the network. The term "Internet appliance"
is often used interchangeably with NC.
network
A network (as applied to computers) typically means a group of computers working
together. It can also refer to the physical wire etc. connecting the computers.
notebook
A notebook is a small laptop with similar price, performance, and battery life.
organizer
An organizer is a tiny computer used primarily to store names, addresses, phone
numbers, and date book information. They usually have some ability to exchange
information with desktop systems. They boast even better battery life than PDAs
but are far less capable. They are extremely inexpensive but are typically incapable
of running any special purpose applications and are thus of limited use.
OS
The operating system is the program that manages a computer's resources. Common
OSes include Windows '95, MacOS, Linux, Solaris, AmigaOS, AIX, Windows NT, etc.
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PC
The term personal computer properly refers to any desktop, laptop, or notebook
computer system. Its use is inconsistent, though, and some use it to specifically
refer to x86 based systems running MS-DOS, MS-Windows, GEOS, or OS/2. This latter
use is similar to what is meant by a WinTel system.
PDA
A personal digital assistant is a small battery-powered computer intended to
be carried around by the user rather than left on a desk. This means that the
processor used ought to be power-efficient as well as fast, and the OS ought
to be optimized for hand-held use. PDAs typically have an instant-on feature
(they would be useless without it) and most are grayscale rather than color
because of battery life issues. Most have a pen interface and come with a detachable
stylus. None use mouses. All have some ability to exchange data with desktop
systems. In terms of raw capabilities, a PDA is more capable than an organizer
and less capable than a laptop (although some high-end PDAs beat out some low-end
laptops). By far the most popular PDA is the Pilot, but other common types include
Newtons, Psions, Zauri, Zoomers, and Windows CE hand-helds. By far the fastest
current PDA is the Newton (based around a StrongARM RISC processor). Other PDAs
are optimized for other tasks; few computers are as personal as PDAs and care
must be taken in their purchase. Feneric's PDA / Handheld Comparison Page is
perhaps the most detailed comparison of PDAs and handheld computers to be found
anywhere on the web.
platform
Roughly speaking, a platform represents a computer's family. It is
defined by both the processor type on the hardware side and the OS type on the
software side. Computers belonging to different platforms cannot typically run
each other's programs (unless the programs are written in a language like Java).
portable
If something is portable it can be easily moved from one type of computer to
another. The verb "to port" indicates the moving itself.
printer
A printer is a piece of hardware that will print computer information onto paper.
processor
The processor (also called central processing unit, or CPU) is the part of the
computer that actually works with the data and runs the programs. There are
two main processor types in common usage today: CISC and RISC. Some computers
have more than one processor and are thus called "multiprocessor".
This is distinct from multitasking. Advertisers often use megahertz numbers
as a means of showing a processor's speed. This is often extremely misleading;
megahertz numbers are more or less meaningless when compared across different
types of processors.
program
A program is a series of instructions for a computer, telling it what to do
or how to behave. The terms "application" and "app" mean
almost the same thing (albeit applications generally have GUIs). It is however
different from an applet. Program is also the verb that means to create a program,
and a programmer is one who programs.
run
Running a program is how it is made to do something. The term "execute"
means the same thing.
software
The non-physical portion of the computer; the part that exists only as data;
the programs. Another term meaning much the same is "code".
spreadsheet
An program used to perform various calculations. It is especially popular for
financial applications. Some common spreadsheets include Lotus 123, Excel, OpenOffice
Spreadsheet, Octave, Gnumeric, AppleWorks Spreadsheet, Oleo, and GeoCalc.
user
The operator of a computer.
word processor
A program designed to help with the production of textual documents, like letters
and memos. Heavier duty work can be done with a desktop publisher. Some common
word processors include MS-Word, OpenOffice Write, WordPerfect, AbiWord, AppleWorks
Write, and GeoWrite.
www
The World-Wide-Web refers to all the publically accessable documents on the
Internet. It is used quite loosely, and sometimes indicates only HTML files
and sometimes FTP files, too. It is also sometimes just referred to as "the
web".