What
does digital mean?
digit - A single character in a numbering
system. In decimal, digits are 0 through 9. In binary, digits are 0 and
1. Describes any system based on discontinuous data or events. Computers
are digital machines because at their most basic level they can distinguish
between just two values, 0 and 1, or off and on. There is no simple way
to represent all the values in between, such as 0.25. All data that a computer
processes must be encoded digitally, as a series of zeroes and ones. The
opposite of digital is analog. A typical analog device is a clock in which
the hands move continuously around the face. Such a clock is capable of
indicating every possible time of day. In contrast, a digital clock is
capable of representing only a finite number of times (every tenth of a
second, for example). In general, humans experience the world analogically.
Vision, for example, is an analog experience because we perceive infinitely
smooth gradations of shapes and colors. Most analog events, however, can
be simulated digitally. Photographs in newspapers, for instance, consist
of an array of dots that are either black or white. From afar, the viewer
does not see the dots (the digital form), but only lines and shading, which
appear to be continuous. Although digital representations are approximations
of analog events, they are useful because they are relatively easy to store
and manipulate electronically. The trick is in converting from analog to
digital, and back again.
This is the principle behind compact discs (CDs). The music itself exists
in an analog form, as waves in the air, but these sounds are then translated
into a digital form that is encoded onto the disk. When you play a compact
disc, the CD player reads the digital data, translates it back into its
original analog form, and sends it to the amplifier and eventually the
speakers.
Internally, computers are digital because they consist of discrete units
called bits that are either on or off. But by combining many bits in complex
ways, computers simulate analog events. In one sense, this is what computer
science is all about.
(http://webopedia.internet.com/TERM/d/digital.html)
digital
Traditionally, digital means the use of numbers and the term comes
from digit, or finger. Today, digital is synonymous with computer.
Digital Means Original The 0s and 1s of digital data mean more than
than just on and off. They mean perfect copying. When information, music,
voice and video are turned into binary digital form,
they can be electronically manipulated, preserved and regenerated perfectly
at high
speed. The millionth copy of a computer file is exactly the same as
the original. While
this continually drives the software industry crazy protecting its
copyrights, it is nevertheless a major advantage of digital processing.
(http://www.techweb.com/encyclopedia/)
digital audio
Sound waves that have been digitized and stored in the computer. The
most common digital audio formats are music CDs and Windows WAV files.
Music CDs are played in CD players as well as CD-ROM readers. WAV files
are stored in the computer or on CD-ROMs and played by a media player
software application. Although also in digital form and stored in the computer,
MIDI music is not considered digital audio. MIDI files contain a coded
version of the musical score, not the actual sound. (http://www.techweb.com/encyclopedia/)
digerati
The "digital elite." People that are extremely knowledgeable about computers.
It often refers to the movers and shakers in the industry. Digerati is
the high-tech equivalent of "literati," which refers to scholars and highly
educated individuals.
(http://www.techweb.com/encyclopedia/)
digitize
To translate into a digital form. For example, optical scanners digitize
images by translating them into bit maps. It is also possible to digitize
sound, video, and any type of movement. In all these cases, digitization
is performed by sampling at discrete intervals. To digitize sound, for
example, a device measures a sound wave's amplitude many times per second.
These numeric values can then be recorded digitally.
(http://webopedia.internet.com/TERM/d/digitize.html)
BITS AND BYTES
Bit stands for binary digit: 0 or 1
A byte is made up of 8 bits
It takes 1 byte to store one ASCII character
ASCII stands for the American Standard Code for Information Interchange
Below are the digital representations for the letters A, B and C:
A 0100 0001
B 0100 0010
C 0100 0011
K stands for kilo and = 1024 (2 to the tenth power)
M stands for mega. A MB, megabyte is about a million bytes (1024x1024)
G stands for giga. A GB, gigabyte is about a billion bytes (1024x1024x1024)
T stands for tera. A TB, terabyte is about a trillion!
RAM is usually measured in MB
Hard disk spaces is usually measured in gigabytes
Common formats
for digital graphics files
(When you create a graphics file, the extension
will relate to the format in which you saved it. But just renaming
the extension on a graphic will not change the graphic format. You
need to use a graphics program which embeds the appropriate formatting
code in the file.)
Format |
Description |
.bmp |
Bitmap - Microsoft Windows format.
For example, monitor background images are in .bmp format. |
.gif |
Graphics Iinterchange Format - The
bit-mapped file format used by CompuServe and a standard form for
Web icons, buttons and other non photo quality images. |
.jpg |
Joint Photographic Experts Group - a compression
technique for color images. It can reduce files to approximately 5% of
the original size; however, some definition is lost. The picture
is divided into tiny pixels, blocks, halved over and over, until the desired
ratio is achieved. The .jpg format is the standard for photo-type
images on the Web. Compression saves memory and loading time. |
.pcx |
A common graphics file format supported by many
graphics programs. Most scanners and FAX modems also use this format. |
.tif |
Tagged Image File Format - A standard
file format for storing images as bit maps. It is used especially for scanned
images because it can support any size,resolution, and color depth. |
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