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What
does digital mean?

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digit - A single character in a numbering system. In decimal, digits
are 0 through 9. In binary, digits are 0 and 1
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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.
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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.
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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.From: Webopedia: http://webopedia.internet.com/TERM/d/digital.html
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digital
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Traditionally, digital means the use of numbers and the term comes from
digit, or finger.
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Today, digital is synonymous with computer.
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Digital Means Original
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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.
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From: Techweb: http://www.techweb.com/encyclopedia/
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digital audio
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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.
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From: Techweb: http://www.techweb.com/encyclopedia/
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digerati
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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
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From: Techweb: http://www.techweb.com/encyclopedia/
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digitize
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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.
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From: Techweb: http://www.techweb.com/encyclopedia/
What are bits and bytes?
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bits and bytes:
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Bit stands for binary digit: 0 or 1
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A byte is made up of 8 bits
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It takes 1 byte to store one ASCII character
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ASCII stands for the American Standard Code for Information Interchange
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The combination of bits (which makes up one byte) below represents the
letters below
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A 0100 0001
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B 0100 0010
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C 0100 0011
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K stands for kilo and = 1024 (2 to the tenth power)
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M stands for mega. A MB, megabyte is about a million bytes (1024x1024)
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G stands for giga. A GB, gigabyte is about a billion bytes
(1024x1024x1024)
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T stands for tera. A TB, terabyte is about a trillion!
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RAM is usually measured in MB
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Hard disk spaces is usually measured in gigabytes
What does bitmap mean?
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bitmap
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A representation, consisting of rows and columns of dots, of a graphics
image in computer memory. The value of each dot (whether it is filled in
or not) is stored in one or more bits of data. For simple monochrome images,
one bit is sufficient to represent each dot, but for colors and shades
of gray, each dot requires more than one bit of data. The ore bits used
to represent a dot, the more colors and shades of gray that can be represented.
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The density of the dots, known as the resolution, determines how sharply
the image is presented. This is often expressed in dots per inch (dpi )
or simply by the number of rows and columns, such as 640 by 480. To display
a bit-mapped image on a monitor or to print it on a printer, the computer
translates the bit map into pixels (for display screens) or ink dots (for
printers). Optical scanners and fax machines work by transforming text
or pictures on paper into bit maps.
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Bit-mapped graphics are often referred to as raster graphics. The other
method for representing images is known as vector graphics or object-oriented
graphics. With vector graphics, images are represented as mathematical
formulas that define all the shapes in the image. Vector graphics are more
flexible than bit-mapped graphics because they look the same even when
you scale them to different sizes. In contrast, bit-mapped graphics become
ragged when you shrink or enlarge them.
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Fonts represented with vector graphics are called scalable fonts , outline
fonts , or vector fonts. The best-known example of a vector font system
is PostScript. Bit-mapped fonts, also called raster fonts, must be designed
for a specific device and a specific size and resolution.
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From:Webopedia: http://webopedia.internet.com/TERM/b/bit_map.html
Formats for
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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