Help
|
|
|
ActionScript:
|
|
ActionScript is the scripting language of Flash which is derived
from ECMA, a European Standard version of JavaScript. ActionScript
is a simplified version of ECMA with some additional shortcuts.
|
|
ADSL - Asymmetric Digital Subscriber Line:
|
|
ADSL is one kind of Digital Subscriber Line transport systems
and can carry as much as 6 Mb/s over a copper line. ADSL thus
makes broadband available over copper phone lines.
|
|
AHG - Ad Hoc Group (MPEG):
|
|
A group of people established to address a specific topic.
|
|
AIFF - Audio Interchange File Format:
|
|
A sound and video file format developed for the Apple
Macintosh platform. Browser plug-ins are available to play
files in this format.
|
|
Anchor:
|
|
An anchor in a markup language is a technical term for
what is popularly known as a "link" between web documents,
or between locations within the same document (in which
case it is identified by a fragment identifier).
|
|
ANSI - American National Standards Institute:
|
|
An organization that defines standards in the information
technology industry and participates in defining network
protocol standards. ANSI is a member of ISO. The ANSI
characters are characters that when preceded with the
ESC (Escape) character they function as a command. ANSI
escape sequences are used to send commands to monitors
or keyboards.
|
|
Archive:
|
|
A collection of stored files not often used, but
nevertheless available. In practice there is no
difference between files of current web sites and
those in the archive. Both are equally accessible.
|
|
ARP - Address Resolution Protocol :
|
|
This protocol is broadcast from an internet server and
all TCP/IP devices on the local network can hear it. When
the machine with the appropriate IP address hears it, it
responds to the ARP request. Each hardware card (i.e. each
NIC, Network Interface Card) has a unique hardware address.
It is also possible to assign a software address to the
card (which would be an IP address). Hardware address information
is obtained from the ARP. Each host has an ARP table that
contains software (IP) addresses mapping to hardware (NIC)
addresses. ARP looks for a hardware address for a given IP
address (the opposite of RARP).
|
|
ATM - Asynchronous Transfer Mode :
|
|
This is a method used for high bandwidth data transfer,
made possible by hardware switches that create a temporary
direct path between two points. This ATM is not to be
confused with the Automatic banking machines encountered
in shopping malls.
|
|
Attribute - Markup language:
|
|
An attribute is a markup command used together with SGML
elements that allow more control over the element. In HTML 4
there are more than 120 attributes. Attribute specify
characteristics of specific elements and cannot be used
with any element. DTDs specify which attributes can be
used with which elements.
|
|
AU:
|
|
AU is a sound file format developed by Sun for the Unix
platform for use on The Internet. It is known as the
Sparc-audio or u-law format.
|
|
Author / web author:
|
|
A web author is a person who writes the markup (HTML)
for web documents. Note that a distinction should be
made between a Web Author (who writes the HTML markup
code), the Web Graphics Designer (who designs a web page
artistically), a Web Designer (who designs the information
and information technology of the website; this term is
also popularly used for the person responsible for all
the authoring aspects mentioned here) and a Web Copy Writer
(who writes the text of the document. In some cases these
functions may be performed by the same individual, but they
are different functions demanding different skills.
|
|
Authoring Tool:
|
|
An Authoring Tool is a program that enables a multimedia
author to create a multimedia product. Authoring tools
typically write many of the functions without the
developer having to know the technicalities of programming
in a programming language. In its simplest form, an HTML
Authoring Tool, for example, automatically completes end
tags. A Multimedia tool may simplify ways in which objects
are placed on a timeline.
|
|
AVI - Audio Video Interleafed :
|
|
A sound and video file format developed for the Microsoft
Windows platform. It is based on the Microsoft Windows
Resource Interchange File Format (RIFF) specification. A
special player is required to play these files.
|
|
Bitmap graphic:
|
Also see Raster. A bitmap graphic is a pixel-based model
for displaying images on display units such as computer
and TV screens. A bitmap graphic contains data about the
color and coordinates of each pixel that needs to be
triggered on the computer screen. Strictly speaking bitmap
graphics are not bitmaps, but pixelmaps.
Bitmaps on computer screens
Bitmap graphic files are typically huge, so for better
computer network transport they are compressed. The most
typical bitmap compression methods on the Web are GIF,
JPEG and PNG. Another method for displaying images on
computer screens is vector graphics.
|
|
BOM - Byte Order Mark:
|
|
BOM is used with UTF-16 characters to avoid confusion with
UTF-8 characters.
|
|
BPS - Bits per second :
|
|
Bits per second refers to the number of bits transferred
per a second through a medium. This unit of measurement
is used to determine the bandwidth of the medium.
|
|
Bridge:
|
|
Bridge is a network related term. A bridge operates on the Data
Layer of the OSI model. A bridge keeps a record of each connected
network segment. Bridges can be used for different protocols and
serve as a filtering mechanism. Because the filter of a bridge can
be configured to allow or disallow certain types of information, it
forwards or stops frames for pre-determined network segments.
|
|
Browser:
|
|
A browser is a software program that interprets markup documents
(such as HTML) and renders them visually on computer screens. At
present the most common way to access The Internet is by means of
a visual browser. With the advent of other media devices a browser
is merely one of the ways used for accessing The Internet. As The
Internet can be accessed by means of other media, such as audio, and
in future smelling and touching, it is technically more correct to
rather speak of a User Agent than of a browser. There are many browsers
other than Netscape or Internet Explorer available for PCs, and there
are "browsers", i.e user agents, for other types of visual devices, such
as handheld devices, projection screens and others.
A parser (which is a part of a browser) investigates the elements and
their relationships and determines the structure of the document. This
is done on the bases of marked document objects. The parser
then passes that information along to a rendering engine which manipulates
the content, typically using associated style sheets to determine how
the content is to be rendered. The most typical manipulation is to
display the content graphically on a computer screen, but it could
also be manipulated to be rendered on other types of devices, such as
speech synthesizers or tactile devices (eg Braille devices).
|
|
Cast:
|
|
In Film and TV "cast " is used for the actors and extras. In Macromedia
Director "cast" includes all the objects (i.e. text, graphics, sound,
video, or Lingo scripting behaviors) used in a production. An object needs
to be identified as a cast member before it can be used. In terms of
function the Director cast is similar to the Flash symbol library.
|
|
CGI - Common Gateway Interface :
|
|
CGI is a method allowing data from client computing devices to pass
into a server for processing. CGI is typically used for capturing data
sent with web forms to servers.
|
|
Character Set :
|
|
There are tens of thousands of characters used in human writing systems.
Unicode lists about 40'000 of these characters. On 8-bit PCs only 128
characters can be mapped to machine code, definitely not enough to handle
all these characters. The Unicode characters are divided into sets of
characters. A PC needs to be set up to use a particular set. Documents that
are distributed over the internet need to specify in which character set
they are written so that devices that receive them can render them correctly
by first adapting to the specified character set.
|
|
Client :
|
|
A client is a device that receives data or programs from a server. This
device may be a different computer, or a 'virtual' computer inside a
physical computer.
|
|
Codec:
|
|
Communications engineering - Acronym for coder/decoder In communications
engineering Codec refers to the analog-to-digital conversion and
digital-to-analog conversion functions that are built into in a single
chip.
|
|
Video compression
|
|
Acronym for compression/decompression in video compression Codec refers
to a software algorithm that eliminates redundancies in data. It throws
away bytes according to the criteria of the different available codec
systems and thus result in smaller file sizes.
|
|
Content type :
|
|
Content type is a technical term (following RFC2045 and RFC2046) used
for describing the content of a web document so that a user agent can
handle the content properly. Web documents can be sent via different
protocols such as HTTP or email (SMTP). In the Web environment the
term Mime type is used
|
|
CSS - Cascading Style Sheet :
|
|
CSS is a style sheet language based on DSSSL conventions. The function
of CSS on the Web is to describe the appearance of visual documents, or
the manner in which a speech synthesizer should render them. A markup
language (such as HTML, or an XML-based language) marks the logical structure
of document content, while CSS describes what the document should look
(or sound) like.
|
|
DNS - Domain Name System :
|
|
The domain name is a human language name for a website at which web
documents are kept. The domain name is the human friendly website address.
This human fridnely name (such as daisy), is mapped to an IP address
(such as 149.98.45.241) -- computers do not directly work with names,
but with numbers. When a web user types in an address such as www.daisy.com,
a nameserver looks up the IP address (in numbers) and sends the requests
there. DNS's are very important in the internet environment. A web address
typically consists of a domain name that needs to be resolved to an IP
address (i.e. the numerical address, such as 215.145.09.189). The server IP
and domain does not necessarily have to be linked to a unique physical
machine -- the mapping may be to a unique virtual machine, which means that
many different domain names and IP addresses may reside on the same
physical server machine.
|
|
Email :
|
|
Email is short for electronic mail. Correspondence can be sent as
electronic documents along networks just like paper correspondence is sent
with postal services. Email messages use a different network protocol (SMTP)
than HTML documents (HTTP), which is why email is not typically sent from
a browser, but from an email program such as Netscape Messenger or MS Outlook.
It is possible to port the SMTP message to HTML so that a web browser can
be used for viewing email.
|
|
File:
|
|
A file is the storage unit of a digital document. Files are typically stored
with file extensions (such as *.html for HTML files, or *.JPEG for JPEG files)
that are linked to the programs that can interpret the digital data of the
document. A digital document typically consists of a set of files. For example,
a web document typically consists of a base HTML file. Associated with this
file there may be any number of graphic files (for images), style files, script
files, etc. All http compliant files can be accessed from a browser as local
files from a client computer.
|
|
.fla - A Flash file extension
|
|
The .fla file extension is used for the basic Flash document file, used in
the development context. After its development, a Flash document needs to
be "published" to the Web. It then gets a .swf extension which can be played
with a Flash player.
|
|
FTP - File Transfer Protocol:
|
|
FTP is a protocol for transferring files between systems, i.e. different
computers in a network. The function of FTP is thus very similar to copying
files between different disks on a PC. The difference is that the files are
transported via a network to a different computer, and not between, say, a
hard drive and a stiffy. FTP uses connection-oriented TCP, thus better than
TFTP (Trivial File Transfer Protocol), which is quicker than FTP. But with
TFTP you have to wait until the entire file is downloaded before you may
discover that there were bad frames and have to start downloading again. FTP
checks the frames while they are downloading.
umgerechnet.
|
|
Gateway:
|
|
A device interfacing networks that use different protocols. It thus translates
between the different protocols. When the definition of Gateway is strict,
it translates only between different high-level architectures, such as, say,
between TCP/IP and IBM's SNA. When the definition is more loose, it translates
between lower-level network types, say between Ethernet and Token Ring. In a
manner of speaking the function of a router and gateway is similar: they both
act as interfacing translators in a network. Gateways are more general than
routers as they translate between most (if not all) protocol layers of the
OSI model. Also see bridge.
|
|
GIF - Graphic Interchange Format :
|
|
GIF is a bitmap method of compressing images, originally developed for
quicker transport of images on The Internet, as file sizes of other graphic
formats were too large. GIF87 is the basic compression scheme, while the
later GIF89a supports transparency and animation.
|
|
Home Page :
|
|
A Home Page is the first web page that is accessed when a domain name
is requested. This page contains links to other pages at the site and
is technically known as the hub document. Technically there is absolutely
no difference at all between a Home Page, Portal, Hub Document, Front Page,
Main Page, First Page, Default Page or whatever other term you may have
come across. They are just marketing names to sell the same thing.
|
|
HTML - HyperText Markup Language :
|
|
HTML is a subset of SGML and was conceptualized by Tim Berners-Lee in 1989.
HTML 0.0 was released by him in 1990. The success of the World Wide Web
is partially due to the simplicity of HTML, the markup language used for
marking documents to be distributed through the Internet. HTML files take
the extension html, but as DOS-based computers could only take 3-character
extensions, it is often written as htm. HTML is a structural language that
serves as a container for document objects. It is like a mammal skeleton.
HTML itself cannot do anything -- for that you need a program. And HTML
should not be used for the appearance of a document (for which you should
rather use a style sheet). From a purist persepctive, the only thing that
HTML does is to mark items and locations in a document with markers (called
tags). User agents (such as browsers) interpret these markers and deliver
the structure of the document in specified ways. For example, if an item
is marked as a Paragraph (in HTML ), a visual user agent will display
its content according to the conventions of paragraph display.
|
|
HTTP - HyperText Transfer Protocol
|
|
HTTP is based on 8-bit transmission and the RFC 822 character set. HTTP 0.9
was released in 1992, while HTTP 1.1 became a formal standard in 2001. HTTP
is the protocol used for transporting web documents over internet lines.
Some of the kinds of files that are handled by this protocol are HTML files,
graphic files, sound files, animation sequence files, script files.
|
|
https - HyperText Transfer Protocol Secure:
|
|
This protocol is the same as HTTP, except that it has security features
built in, usually some kind of encryption scheme. Users need keys to start
the secure level, otherwise files cannot be accessed.
|
|
IP - Internet Protocol :
|
|
IP is defined by RFC791 and RFC1349. IP provides a datagram service
between hosts on a TCP/IP network - IP thus runs "on top of" TCP. It
routes the packets of data that are transmitted to the correct host.
IP also takes apart datagrams and puts them back together again. The
IP (i.e. IPv4) address of a device is a hierarchical and numerical 32-bit
address such as 123.143.221.225 (with numbers ranging from 0-255 in each
block). IPv6 is a 128-bit system, permitting many more IP addresses than
IPv4. Older server architecture allowed only one IP address per box, which
meant that you needed a different server for each IP address. Soon "virtual
boxes" aliasing was possible allowing more than one IP address to be on
the smae box, and allowing each such IP to alias to a different domain name.
|
|
ISDN - Integrated Services Digital Network :
|
|
ISDN is a digital communications standard that works over analog phone
lines. ISDN is a point-to-point communication system. Technically ISDN has
a B and D channel. A B Channel (bearer channel) carries voice and data
at 64Kb/s, while the D Channel (data channel) handles signaling at 16Kb/s
or 64Kb/s, depending on the service type. The K for "kilo" in ISDN
terminology may be confusing to people from the IT environment. This K
literally means 1000 (i.e. 103), while the K in IT means 1'024 (i.e. 210).
|
|
ISO - International Standards Organization :
|
|
The ISO is an international body that certifies standards ranging from
visual signs (such as the i-sign for information, seen at places such
as airports and information kiosks) to language characters (such as
proposed by ANSI and ASCII ). SGML standards are also decided by the
ISO since it became a standard in 1986. HTML is a subclass of SGML,
and complies in that respect to ISO standards, but HTML itself is
not an ISO standard.
|
|
ISP - Internet Service Provider :
|
|
An ISP provides users access to the Internet. This access is possible
through dial-up connections such as through analogue or ISDN modems.
Access is also possible through many other means, such as diginet
lines, ADSL, microwaves, radiowaves, etc.
|
|
Java:
|
|
Java is an object-oriented programming language released by Sun in
1992. Java is similar to C++ but was introduced due to some problems
experienced with C++ such as memory leaks and multiple inheritance.
Java is both compiled and interpreted, and architecture neutral. It
can thus run on a very wide range of devices with minimum effort. Java
is further portable and multithreaded (many things can happen
simultaneously).
|
|
JavaScript :
|
|
JavaScript is a scripting language originally developed by Netscape
in 1995 for Netscape 2.0. It was originally called LiveScript, but
renamed JavaScript as it was viewed to be complementing Java. JavaScript
is an interpreted scripting language that is typically executed by the
browser (i.e. on the client-side). However, there is also server-side
JavaScript which is executed on the server. JavaScript 1. 0 has become
a standard, known as ECMAScript.
|
|
JPEG / JPG - Joint Photographic Experts Group :
|
|
Pronounced jay-peg. JPEG is a bitmap compression format for images.
The proper abbreviation is JPEG, but DOS-based computers could only
take a 3-character extension, so you will often see the shortened
version: JPG. JPEG is based on a 24-bit color palette, but it is lossy,
which means that it drops information that is compressed out. Compression
ratios may range from 10:1 to 20:1 and most graphic application programs
(such as Adobe Photoshop) allow you to choose the compression rate.
Obviously, the more compressed, the more data is lost, but the less
compressed the larger the files size of the image. It takes considerable
experience and skill to play around with different modes and pallettes
as well as compression ratios to get a good quality result with a
relatively small JPEG file size. JPEG is typically used for complex
images and photographs. It supports 16.7 million colors.
|
|
Keyframe:
|
|
A keyframe is a special kind of frame that contains info about
changes in the properties of an object. For example, animated movement
may proceed from a starting point to an end point through time. Each
of these points would be a keyframe as their respective frames indicate
where the animation begins and ends through time.
|
|
Layer:
|
|
In CSS objects can be displayed on top of one another and described as
such along the z-axis. In design programs, such as Adobe Photoshop and
Macromedia Flash, objects (visual or audio) can be placed in separate
layers to facilitate the design process. For example, it is easier to
manage the design of a complex image if its components can be separated
into different layers.
|
|
Link:
|
|
Link is the short form for "hyperlink". A link "links" documents, or
document fragments to one another. When a user activates a link, the
document changes to the position indicated by the link. In web pages
links were originally underlined to indicate the link. With style sheets
a textual link can take on any design features. Images and other objects
can also be used as links.
|
|
mailto - email (electronic mail) :
|
|
The mailto method is used to activate "send email" from a web page. This
method starts the email program on the client. Originally email was
handled by special programs that were totally separate from web browsers,
but later versions of web browsers could handle email to such an integrated
degree that users are not even aware that they are busy with a different
service.
|
|
Media type :
|
|
Content stored in electronic format can be delivered on many different
types of devices. The following media are presently recognized as valid
delivery systems on an internet. This list may be expanded in future
versions: Screen, tty, tv, projection, handheld, print, braille, aural,
all. See MIME and Content type.
|
|
Movie:
|
|
When the film industry began images could "move" and the term moving
pictures, shortened to movies, began to be used. In Macromedia Flash
and Director a movie is a multimedia application for the Web that may
contain graphics, text, sound and video. A Flash movie also contains
some level of user interactivity. The basis of a Flash movie is vector
graphics, but it can contain bitmaps and other media such as sound and
video.
|
|
MPEG - Motion Picture Experts Group :
|
|
MPEG consists of a group of international experts that write ISO
standards for moving images. There are several MPEG standards
(see below).
|
|
MPEG-1 :
|
|
MPEG-1 is used for digital video at low compression rate. It allows
for image compression for up to 1.5 megabits per second. MPEG-1 is
the standard on which Video CD and MP3 are based. Compressed video
to be used on the Web in its present status would rely on MPEG-1.
|
|
MPEG-2 :
|
|
MPEG-2 is used for digital video at low compression rate. It allows
for image compression for up to 10 megabits per second. MPEG-3 is
the standard on which such products as Digital Television set top
boxes and DVD are based.
|
|
MPEG-3 :
|
|
MPEG-3 is used for digital video at low compression rate. It allows
for image compression for up to 40 megabits per second. In practice
this is hardly implemented as MPEG-2 is sufficient for most cases.
|
|
MPEG-4 :
|
|
MPEG-4 is used for integrated multimedia and a compression standard
for long audio or video files with limited digital storage media
(DSM) or low bandwidth availablity. MPEG-4 is the standard for
multimedia for the fixed and mobile web.
|
|
MPEG-7 - Multimedia Content Description Interface:
|
|
MPEG-7 is an XML-based standard for the inclusion of metadata in
multimedia products. It makes possible interactive TV and faciltates
the managing of multimedia stock. It is the standard for description
and search of audio and visual content.
|
|
MPEG-21 :
|
|
Multimedia Framework. The purpose of MPEG-21 is to build an
infrastructure for the delivery and consumption of multimedia
content.
|
|
MP3:
|
|
MP3 is a sound compression format based on MPEG-1, Layer 3, which
is the audio compression format used in the MPEG-1 algorithm.
|
|
NTSC - National Televisions Standards Committee :
|
|
An analogue video standard used in the United States of America
and Japan. The frame rate is 30 frames per second (fps). SECAM scans
the cathode ray tube (CRT) horizontally 525 times to form the video
image. Other standards are PAL and SECAM.
|
|
OSI - Open Systems Interconnection model :
|
|
Work began in 1977 by the ISO to simplify communication between
different computer systems. This work resulted in the OSI which
is a model specifying functions on a network. OSI does not specify
how the functions are to be performed.
|
|
PAL - Phase Alternation Line:
|
|
an analogue video standard used in Western Europe and Great Britain,
Africa, Australia, China, South America. The frame rate is 25 frames
per second (fps). PAL scans the cathode ray tube (CRT) horizontally
625 times to form the video image. Other standards are NTSC and SECAM.
|
|
PICS - Platform Independent Content Selection :
|
|
PICS is an infrastructure for associating labels (metadata) with
Internet content. These labels are used for code signing, privacy,
and intellectual property rights management. PICS was originally
designed to assist in the control of internet content -- to prevent
children and sensitive users from stumbling upon unwanted sites.
|
|
Pixel - Picture Element :
|
|
A Picture Element (pixel) is a single addressable location on a
computer screen, i.e. the smallest unit of display that can be
controlled by software. Size:The actual size of a pixel is relative,
depending on the quality of the screen, or how the screen is configured.
A web author can therefore never be sure of the exact size or quality
in which documents would be rendered. Color: Color can be assigned to
a pixel, but the software color palette is translated into hardware
according to manufacturer specifications, so the color of a pixel is
also not absolute. sRGB is one attempt to standardize on the delivery
of color.
|
|
PNG - Portable Network Graphics:
|
|
W3C recommendation on 1 October 1996. PNG is a bitmap compression
method for image files. This format is recommended by the W3C to be
used instead of GIF. PNG supports 16.7 million colors, it is lossless
and also supports index color, grayscale, true color, and is streamable.
It is thus the best compression method (better than GIF or JPEG) for
use on the web.
|
|
PPP - Point-to-Point Protocol :
|
|
A driver used for accessing a network communications protocol over a
phone line. PPP allows connection to the TCP/IP protocol which is the
basic internet protocol. A dial-up user gets connected to The Internet
via PPP.
|
|
QuickTime:
|
|
The Apple QuickTime format (in *.MOV files) is a digital video format
used for transporting compressed video files through The Internet.
|
|
RFC - Request for Comment :
|
|
An RFC is a documents that states protocol standards, proposed
changes, information bulletins about the internet. The name is somewhat
of a misnomer in some cases as an RFC document often serves as the
standard which is already being accepted as valid from a certain date
until it is officially changed. An RFC may also be an explanation of an
existing practice.
|
|
Rollover image :
|
|
A rollover image is used in the context of navigation where an image
button, that serves as a link elsewhere, changes into a different image
because of some or other associated pointer behaviour (e.g. mouse down).
|
|
Router:
|
|
A router functions like a traffic officer, directing the flow of data
to targets. It receives a packet of data, reads the address, and passes
it on to the next machine in the line. In the beginning of the internet
routers were typically in a separate box so as to reduce the load on
the web (i.e. HTTP) server. However, router software may reside on the
HTTP server. A router operates at the network level of the OSI model.
For each protocol there would be a different router as they are protocol
dependent. However, routers do not bother about different network
topologies and can therefore be used to pass data along different
networks such as Ethernet and Token Ring. A router relates to a bridge
and a gateway. A bridge allows any frame that is allowed to be passed on
to a segment, while a router only allows addressed frames. A router is
thus more intelligent than a bridge. However, routers work much harder
than bridges, and therefore their throughput is much lower.
|
|
Scene - a segment of the entire movie :
|
|
In Flash a scene consists of a number events that the developer regards
as constituting a sub-theme of the entire Flash movie. A Flash movie
should be divided into scenes to facilitate the management of the project.
Scenes thus segment the production into smaller more manageable parts.
|
|
Score:
|
|
In music the score contains the notes of a composition. It is a synonym
for sheet music. In Macromedia Director the term score means timeline
and used to indicate the position of objects within a time-based production.
|
|
SECAM - Sequential Couleur avec Memoire :
|
|
An analogue video standard used in France, Eastern Europe and previous
USSR countries. The frame rate is 25 frames per second (fps). SECAM scans
the cathode ray tube (CRT) horizontally 625 times to form the video image.
Other standards are PAL and NTSC.
|
|
Server :
|
|
A server is computer software that "serves" documents or programs to
another computer which requested them. In such instances the requesting
computer is known as a "client". A server could also just be software
that serves files to a client program on the same box. On the web the
most used server is the HTTP server. Other types of servers are FTP,
NNTP (for news), SMPT (for email) , etc.
|
|
SGML - Standard Generalized Markup Language :
|
|
ISO 8879 of 1986. SGML is an international standard for the transport
of documents in a format independent of the device, system or application.
The technical detail need not bother you as HTML author. But note that
this standard is also constantly in the process of being revised. In 1993,
for example, Korean Hangul characters have been added to the standard. Also,
there is presently a restriction on the total of codepoints allowed in the
document character set. This is also in the process of being revised. SGML
is the granddaddy of HTML and XML. HTML is an application of SGML, while
XML is a metalanguage based on SGML, used for creating XML applications.
|
|
SMTP - Simple Mail Transport Protocol :
|
|
This is the mail protocol used on The Internet. Email can be sent to a
transport engine (i.e. a mail server) that stores and deliver mail. Only
when a session is established by the agent (i.e. the user's mail program)
is mail sent to the receiving agent. SMTP is defined by RFC821 and RFC1441.
Message format is defined by RFC822, the Standard for ARPA Internet Text
Messages.
|
|
Sound:
|
|
The following sound file types are used for compressed sound files
through The Internet: WAV, AU AIFF, MIDI.
|
|
SSL - Secure Sockets Layer :
|
|
A secure HTTP protocol, identified with https.
|
|
Streaming:
|
|
Multimedia files are typically large. A user does not want to wait
until the entire file is received through an internet connection.
Streaming makes possible that a file's content can be viewed before
it is completely received. The data of the file is continuously sent
from the server. While loading the user can begin viewing the streamed
data. Special server software makes streaming possible.
|
|
.swf - A Flash file extension :
|
|
The .swf file extension is used for a Flash document that can be played
with a Flash player. Before it is published, a Flash document, while it
is being developed, has the extension .fla.
|
|
telnet :
|
|
This method is used for accessing a remote computer and use it as if
it is the one right in front of you. The interface is text-based (on
the command line), so you do not see the windows of the remote system.
|
|
TIFF - Tagged Image File Format :
|
|
TIFF is an image file format system used in graphic programs. TIFF is
a compressed bitmap format.
|
|
Timeline:
|
|
Timebased media progress along as time passes. During the production
of such media it is important for an editor to know where in this laps
of time a particular instance of an object (visual or audio) is located.
Production material is therefore mapped to some or other timeframe, which
is visually presented as a line. The basis of the timeframe is usually
real time in hours, minutes, seconds, milliseconds.Macromedia Flash uses
the term timeline in the above sense, while Macromedia Director uses the
term score, which is quite misleading.
|
|
UCS - Universal Character Set :
|
|
Computers originated in the USA where English is the dominant language.
Computers thus basically use a character set that is biased toward
English (the ASCII character set). As computers became used in other
cultures where other characters (such as ö, ë, ù, é in some European
languages) are used, the basic set was extended to include these
characters. This extended character set is known as ISO 8895. However,
even this extended ASCII character set is not enough to cope with all
the variety of characters found in the many different languages of the
world. The UCS was formalized and contains thousands of characters
used by communities all over the world (also see Unicode).
|
|
URL - Universal Resource Locator :
|
|
The URL is a subset of URI and is an identifier (an address) linked
to each location available on the Web, such as a machine server, or
software server. It has become customary to speak of URL's instead
of URI's for web addresses.
|
|
User:
|
|
A User is a person who uses the internet, and typically requests
an HTML document from a user agent (i.e. typically a browser). The
most common user is presently a person who browses through the Web
by means of a web browser. However, HTML documents can be rendered
in different ways such as in the audio medium. The user then does
not browse the Web, but listens to the document.
|
|
Vector Graphics :
|
|
Images decribed by vector graphics do not contain data for each
pixel (as is the case for bitmap graphics), but data about certain
standard image forms (such as lines, curves, gradients, animation,
and filter effects). A straight line, for example, would be described
by its start and end points, and the fact that it is a line. It should
be evident that this line object contains much less data than a bitmap
line (which needs to describe each pixel). Vector graphics are easily
scaleable without losing any quality. SVG is a relatively new XML-based
vector graphic format developed for the Web.
|
|
Video:
|
|
There are three different video formats for video files that are
transported through The Internet: AVI, MOV and MPEG. Video is
technically speaking a series of frames that pass by so quickly
that our eyes are fooled into viewing content as smoothly moving
images. For smooth observed movement we need about 25 frames to pass
by our eyes every second. That means 25 bitmap images every second.
The web is far too slow for that to be of any practical use. One way
of reducing the number of frames is to take out some frames. Another
way to reduce file size is to display the video in a small screen window.
|
|
WAF - Wireless Application Forum :
|
|
WAF was founded in 1995 by Unwired Planet and joined by Nokia,
Ericsson, and Motorola to enable a pseudo web-experience for cell
phones. The main components of its technology are WAP and WML.
|
|
WAV:
|
|
A wave file (*.WAV) is a compressed waveform file used for
transporting sound files through The Internet. Waveform is a
Microsoft Windows format, but such a file can be played back on
other platforms (Such as Macs) with the necessary player software.
|
|
Web Address :
|
|
A web address may consist of a unique domain name or of a name
that is part of a subdirectory of a domain name. Every Web Page has
its unique Web Address, technically known as a URI. Example of a
Domain Name web address:
http://www.vish4.com
|
|
WWW - World Wide Web :
|
|
The World Wide Web was the name used by Time Berners-Lee for a
project he envisaged in 1989 to make possible a universal document
exchange by means of computer networks, particularly the Internet.
The protocol he wrote for transporting documents is HTTP, and the
Domain Name System uses WWW as the service name. Originally only
text documents (saved as HTML files) were accessed with browsers
that could receive and display WWW documents. Nowadays a browser
seemlessly integrates other services (such as mail, graphics,
animation, scripts, video and music), and devices other than PCs
can be used to access web documents.
|
|
XML - Extensible Markup Language :
|
|
W3C Recommendation 10 February 1998. XML is a subset of SGML and
is a metalanaguage providing the rules and conventions to be used
to create other languages following these rules. These other languages
are called XML-applications. There are thousands of XML-applications
such as MathML (Mathematics Markup Language), CML (Chemical Markup
Language), CDF, OSD, HDML (Handheld Device Markup Language), RDF (Resource
Description Framework), MML (Music Markup Language) XML documents can
be created with a text-editor just like HTML documents. XML, however,
is much stricter with its rules. XML documents need to be well-formed
(e.g. element names, i.e. tags, are case sensitive and must be ended,
unlike HTML) and for data vailidity they also need to be valid (i.e. be
associated with a DTD which contains definitions of and relationships
between elements).
|
|
XSL - Extensible Stylesheet Language :
|
|
W3C Working Draft 21 Apr 1999. XSL is a style sheet language based
on the principals of XML and more powerful than CSS. XSL consists of
two main components: XSLT (which concerns the document tree) and formatting
(which is based on CSS 2.0).
|
|
YUV - also known as YCC, or analog YUV, or YCbCr :
|
|
YUV is a color model that decomposes color in three components:
Y: Luminance (or chrominance)
U, Cb: Chroma channel, U axis, blue component
V, Cr: Chroma channel, V axis, red component
YUV is used in JPEG compression, as well as in the European TV standard, PAL.
|