A small program in the Java language
which can be included in a page in HTML.
ASCII (Standard American
Code for Information Interchange)
It is an international standard for the numerical
codes used to represent internally in a computer any alphabetic, numeric
and special characters.
B
Backbone
A group of high-speed lines comprising the main
infrastructure of a network.
Bandwidth
A term referring to the speed of transmission in
a network, or, alternatively, the carrying capacity of a connection.
BBS (Bulletin Board System)
A private service providing electronic mail and file downloading, offered
through a computer linked to the phone system (a server).
The connection is usually point to point, i.e. for each phone line linked
to the system, only an external computer (client), may call the BBS.
Bit (Binary DigIT)
A binary digital number which uses the base 2 (0 or
1) system. It is the smallest unit of information of a digital computer.
BITNET (Because Itıs Time to NETwork)
A global network of educational sites, built apart from the Internet
(but connected to it via a gateway), which essentially
carries electronic mail and discussion lists. Due to the spread of Internet,
it is now in decadence.
Bps (Bits Per Second) -
Unit of measurement of the speed of a digital transmission through
a line, or of a modem (how many bits
it transmits in a second).
A group of 8 bits, used to represent a character
of information in a digital computer. It is also a measure of the size
of a computer's memory.
C
CGI (Common Gateway Interface) -
A group of rules which specifies as one should carry
out communication between a WWW server and another program located in the same
machine.
Chat
Electronic form of on-line, real-time dialogue through the Internet
or a BBS . There are chats based on text, voice or video,
or any combination thereof.
client
A software used to communicate and to exchange data with a server,
usually in another computer. A browser such as the Netscape
is an example of a specific client for WWW.
D
Dial Up
An access method to the Internet by using a normal phone line connected
to two modems.
Distribution List
A system for simultaneously sending email to a list of
subscribers or group of users.
Discussion List
A distribution list set up specifically to allow the discussion or
cooperative work among several users and/or on a given topic.
Domain
The name that identifies a server in the Internet. It
can consist of two or more parts, separated by dots, which identify a
hierarchy of domains and subdomains. For example, the domain:
nib.unicamp.br
icorresponds to a machine (nib) in an
institution or local network (unicamp) in
Brazil (br).
A domain must also correspond to a given computer, but a computer may
have more than a domain name. Each domain is associated to a number that
identifies the machine linked to the Internet, and which is called IP
Number
E
E-mail (Electronic Mail)
System of exchange of messages among two computers
linked to the Internet. An user has an electronic post office box, that can be
accessed by means of a special program.
Ethernet
A communication protocol among computers connected to a local network..
It can be used with any computer type and it reaches speeds of 10 megabits
per second (Mbps) or 100 Mbps (Fast Ethernet)
F
FAQ (Frequently Asked Questions )
On-line documents containing the most frequent questions and answers
related to a certain subject, a discussion list,
a site in the WWW, etc.
Finger
An Internet service that allows us to determine
whether a specific user exists and is connected to a certain server. Many
servers, for reasons of safety, don't allow the access through Finger.
FTP (File Transfer Protocol)
A group of rules or protocol which permit the transfer of binary files
or of text among two computers linked to the Internet. A server that allows
that access is named a FTP server. There is a method to copy files without
need of having a password, called anonymous FTP, which gives to the user
free access to the public areas of a server.
G
Gateway
Generally, it is a system that gives simultaneous
access to two computer networks, as for example, between a local net and the
Internet, or between two different networks (for example, Compuserve and
Internet), channeling the traffic and, if necessary, translating different
protocols.
GIF (Graphics Interchange Format)
One of the most popular compressed digital image formats available
in the Internet, is was developed by Compuserve. It is automatically recognized
and displayed by most browsers. See also JPEG
A system or protocol used to access textual information in the Internet,
in the form of simple menus. It consists of a client gopher, located in
a personal computer or terminal, that allows access to any gopher server
linked to the Internet. It is now in decadence, due to the prevalence of
other access methods using hypertext, such as
in the WWW.
H
Home Page
it refers to the main page of information in a site
in WWW. It can be a personal page or of an institution, or of a certain
information resource.
Host
It refers to any computer in a network that offers access services
to other computers. It also refers to the computer that offers access to
the Internet by means of dial up or dedicated lines.
HTML (HyperText Markup Language)
A language used for marking up texts and images in home pages and other
documents in order to be visualized in the WWW, and
that implements the functions of the hypertext.
When receiving a page coded in HTML from a WWW server,
the client software (or browser)
transforms it into an hypermedia display.
HTTP (HyperText Transport Protocol)
The protocol used by Internet to transmit files coded in HTML
between a server and a client,
in the WWW.
Hypertext
A document that contains links to other points
in the same document, or to other documents, text files or images available
in some server linked to the Internet. On being clicked on by the mouse,
it causes the HTTP to look for and to transmit the
file indicated by the client.
Hypermedia
The technology or its product, which combines elements of hypertext
(non linear navigation through a document or system or documents) and multimedia
(text, images, sound, etc.)
I
Intranet
A local network that uses the same protocol, systems and programs used
in the Internet for remote access, file transfer, electronic
mail and access to hypertext and multimedia. It is a kind
of private internet.
IPNumber
(Internet Protocol Number ) - it is a numeric code, constituted
by four numeric segments between 0 and 255, used by the Internet (TCP/IP
protocol ) to uniquely identify a host or machine
linked to the Internet. Example: 165.113.245.2. An IP may be symbolically
associated to one or more domain names, which are easier to remember. When
the SLIP or PPP protocols are
used to connect a computer to the Internet, it receives a temporary
IP number that is later lost when disconnecting.
IRC (Internet Relay Channel)
A protocol of the Internet that allows an on-line dialogue (or chat)
between several clients linked at the same time to
an IRC server. A chat may occur between public channels
(multichat) or between any two clients (private chat).
ISDN (Integrated Digital Services Network)
A technique of transmission of digital data by means of normal phone
lines; it allows the integration of voice, text and images. It uses speeds
between 56 to 128 thousand bps.
Java
A programming language specifically developed by the computer company
Sun Microsystems to allow the execution of programs by a browser,
after transmission by the Internet. Using small programs in Java, called
applets, several non available functions in HTML can be added to a home page.
JPEG
A standard for compressed static photographic images and graphics.
It is automatically recognized and displayed by most browsers.
See also GIF.
K
Kilobyte
Approximately 1000 bytes (the correct number is
1024, for reasons of construction of digital computers),
L
Listserv
A program that allows the implementation of distribution lists or discussion
lists in BITNET and in the Internet. There are
other similar programst in operation, such as Listproc
and Majordomo.
Login
The process of receiving access to a host or remote
computer, requiring a user name or identification code, plus a password,
When these are validated by the host, access is gained to it.
An interface and a specific protocol to specify
sequences of digital polyphonic sounds, and to connect electronic musical
instruments to digital computers.
MIME (Multipurpose Internet Mail Extensions)
A standard that allows the transfer of binary files, such as programs,
images, voice, etc., through the email. When files
of these types are sent via a MIME-compliant program, they are coded in
the origin to a sequence of ASCII text characters, and then decoded in the
destination.
Mirror
A complete copy of a certain site or directory, in another host
linked to the Internet. It usually has the aim to facilitate the access to
sites which are heavily visited or to increase the access speed to servers
located in faraway places.
MPEG
A standard for compressed digital video (movie) files. Files in
this format have the extensions .MPG or .MPEG. You will need a plug-in
in order to see a movie in this format in your browser.
Modem (MOdulator, DEModulator )
An electronic device or equipment connected to a computer that allows
the digital transmission of data through the normal phone system. It transforms
the bits into sequences of audible tones, and sends
them down the line in a speed which is measured in bits per second (
bps).
Mosaic
Ther first graphics-based browser or client
for the WWW, developed by US National Center for
Supercomputer Applications ( NCSA). It has now been
largely substituted by the Netscape and Internet
Explorer
commercial browsers
Multimedia
A technology or its product which combines in a
single program or access method (CD-ROM, network, etc.) data and information
in several medial, such as text, static and dynamic images or graphics,
audio and video segments, etc. It includes interactivity functions, i.e.,
it allows for a two-way interaction between the user and the product. See
also hypermedia.
N
NCSA (National Center for Supercomputer Applications)
An important American research center, located in the state of Illinois,
which has developed Mosaic, the first graphic browser
for the WWW, setting several
important standards in this area.
Netscape Communicator
One of the graphical browsers or clients
for WWW of bigger success and dissemination, it
was developed based on in the NCSAMosaic,
and marketed by the company of same name. It exists for several platforms,
like Windows 3.1, Windows 95, UNIX and Macintosh.
Newsgroup
The name given to a kind of news distribution service, in the form
of a bulletin board system, called USENET. It has
the same purpose of discussion lists, but it is not distributed via email.
Instead, you must have a specific client, called a newsreader,
which connects to a newsgroup server. The latest
versions of WWW browsers have inbuilt newsreaders.
NIC (Network Information Center)
A server or organization that centralizes information on the Internet,
such as white and yellow pages, names of domains, etc. The best knwon NIC
is called InterNIC, which is general information center on the Internet.
Node
A generic name given to any computer linked to a network.
P
Packet Switching
A digital message transmission system used in
computer networks, which divides all messages into smaller, fixed-size
segments called packets.
Password
A private sequence of characters, used to gain access to a server
or host
computer.
Plug-in
A software that adds computational resources to a WWW client
or browser. For instance, they are needed to to
run video clips coded in the MPEG format, or to hear
audioclips coded in the Real Audio format, etc. Thus, the user needs to
install the plug-ins beforehand. Most of the plug-ins are available as
freeware or shareware in the Internet (a list of all the plug-ins for the
Netscape browser can be found in www.netscape.com)
POP (Post Office Protocol)
It is a protocol that allows the a software client's communication
with an email server, through SLIP or PPP.
Used by programs such as Netscape Mail, Eudora,
etc. In order to access his email via a POP protocol, the user must
have a POP account set up for him in his Internet host.
Port
The channel through where the information enters and leaves a computer
linked to the Internet, or host. Usually, each Internet
service or protocol works with a predetermined port, which receives a number.
This is the number which sometimes appears in a WWW URL address after the :
character.
PPP (Point to Point Protocol)
A serial communication protocol which allows the connection of any
two computers using TCP/IP, through a modem
and a phone line. It is generally considered better and safer than
the other protocol of that type, SLIP.
R
RealAudio
A proprietary technology of streaming audio, developed by an American
company, which is able to play a sound file as it comes from the server.
All RealAudio files have the extension .RA or .RAM. The same company
had developed RealVideo, a streaming video
technology. You need a plug-in added to your browser, in order to hear
RealAudio or RealVideo files (available at www.realaudio.com)
RLOGIN
An Internet service similar to telnet.
Router
A combination of special hardware and software used to manage the connection
between two or more computer networks, by establishing the routes to be
followed by message packets.
S
Server
A combination of hardware and software which is used to provide access
services to files and programs to external computers connected to a network,
called clients.
SLIP (Serial Line Internet Protocol)
A serial communication protocol which allows the connection of any
two computers using TCP/IP, through a modem
and a phone line. The other protocol of that type is PPP.
Socket
It refers to a software that, when added to an operating system, it
establishes a protocol, or communication language, with another computer. Windows
3.1, for example, needs a TCP/IP socket (named
WinSock) in order to communicate with the Internet. Trumpet is the best
known WinSock of this type. Both Windows 95 and OS/2 come with pre-installed
sockets.
T
TCP/IP (Transmission Control Protocol/Internet
Protocol)
A group of protocols or communication rules that is the base of operation
of the Internet and of the intranets. In order that a
computer of a certain model and/or operating system is able to communicate
with the Internet, it is necessary that it has the TCP/IP protocol.
Telnet
A software which allows access to a remote computer, or host,
through the Internet. In this way, a client computer is able to function as it were a
remote terminal of that host, by gaining access via a login name and password.
Terminal
A device that works as a client of a central
computer or host in a network. It may simply consist
of a keyboard and a video monitor (the so-called dumb
terminal) or of a complete microcomputer using a special terminal
emulation software (such as Windows Terminal, HyperTerminal, ProComm,
or others). In this case, it is called an intelligent
terminal.
U
UNIX
A computer operating system invented in the 70s. It allows multiuser
(several users can use a central computer at the same time) and multitasking
(the same computer can execute several programs at the same time) processes.
It contains the original TCP/IP, therefore it is
used by 9 among 10 servers (hosts) in the Internet,
URL (Uniform Resource Locator)
A standardized form of specifying the address of any resource, site
or existent file in a WWW server. The URL includes
specifications for the protocol to be used (for example, HTTP),
the machine, or node, where the informationis located
(for example: www.nib.unicamp.br), the directory (for example: svol) and
the file (for example: index.html), giving a complete and unique address:
http://www.nib.unicamp.br/svol/index.html
USENET
A global network of discussion groups and newsgroups,
based on special servers that place those news and messages in a public
area which can be accessed through the Internet.
W
WAIS (Wide Area Information Servers)
A software and service in the Internet which allows
the buildup of searchable keyword indexes using text files. In this way,
Internet servers are able to provide search services to its users.
WWW (World Wide Web)
The set of all servers and the access services
to information provided by them, using hypertext and multimedia,
based mainly on the HTTP protocol .
