Confused by the latest spate of Internet-related acronyms
flooding the computer industry? You're not alone. There are so
many unexplained acronyms that understanding them is like trying
to communicate in a foreign country when you
don't know the language and have forgotten your translator.
To help you feel more at home, here is a concise explanation of
some common Internet acronyms from ADSL to WWW. Don't be caught
off guard the next time an Internet guru throws the latest
jargon at you. Instead, be prepared. Learn the language
ahead of time so you don't feel out of place when terms such as
ICMP and PPTP are being thrown around.
ADSL (Asymmetric Digital Subscriber Line) A digital
phone-line technology that supports high-speed connections to
the Internet using ordinary copper telephone wires. Proffered
by AT&T as an ISDN replacement for Web surfers, ADSL is
"asymmetric" because uplink speeds (64 Kbps) differ markedly
from down-link speeds (up to 6 Mbps). ADSL is currently
available only in selected markets.
ARP (Address Resolution Protocol’s) protocol that
translates Internet Protocol, or IP, addresses
(for example,128.10.3.42) into physical network addresses.
One of the many members of the TCP/IP protocol suite, ARP is a
key player in the process that allows a packet of data addressed
to a particular Internet
host to find its destination. See also DNS, RARP, and TCP/IP.
CGI (Common Gateway Interface) A means for transferring
information that users have typed into forms found on Web pages
to scripts or programs run on a Web server, and vice versa. Two
of the most common uses for CGI are performing database queries
in response to user input and creating dynamic Web pages by
assembling HTML data on the fly. The most popular language for
writing CGI programs is Perl.
COOKIE A cookie is a technical term for a piece of information
that's sent by a web server (such as ad.linkexchange.com) to a
browser (such as Netscape Navigator or Microsoft Internet Explorer)
and then back again from the browser to the web server. Even though there
really isn't much to cookies, they allow you to do some really neat
things like:
DNS (Domain Name Service) The online database that
correlates Internet IP addresses (for example, 128.10.3.42) to
human-readable domain names such as pcmag.com. The database
isn't stored on any one computer; rather, it's distributed
among thousands of name servers spread throughout the Internet.
FAQ (Frequently Asked Questions) A document with answers
to you guessed it-frequently-asked-questions. FAQs are widely
available online and cover a broad spectrum of topics ranging
from gourmet cooking to the inner workings of TCP/IP.
FTP (File Transfer Protocol) A widely used TCP/IP
protocol for transferring files from one machine to another.
Internet users may use FTP applications to log in to FTP servers
and download files. No restrictions are placed on
file contents; they may contain text or binary data. Files may
be protected from unauthorized access using authentication
control, or they can be made public with anonymous FTP which
doesn’t require a login name or password. See also TFTP
HTML (Hypertext Markup Language) A text-based page
description language that uses tags to describe formatting
idioms and allows richly formatted documents to be created
using everyday text editors. HTML is the language used to
create Web pages. See also HTTP and VRML.
HTTP (Hypertext Transfer Protocol) The text-based
protocol that serves as the official language of the World Wide
Web. HTTP defines high-level commands, or methods-such as GET
and PUT-that browsers use to communicate with Web servers. The
GET command requests a page of HTML data, a .GIF file, or other
resource from a Web server in preparation for displaying it in
a browser window.
See also HTML.
ICMP (Internet Control Message Protocol) The TCP/IP
protocol used to send control and error information regarding
IP datagram transmissions. When an IP datagram cannot be
delivered to its destination, perhaps because the machine at
the destination is temporarily out of service or message
traffic is too
heavy, a router may use ICMP to notify the sender of the
failure. See also IP.
IGMP(Internet Group Management Protocol) The TCP/IP
protocol that permits Internet hosts to take part in IP
multicasting-an efficient means of broadcasting messages to
groups of computers.
InterNIC (Internet Network Information Center) The
administrative organization that is responsible for, among
other things, allocating domain names and distributing RFCs.
Funded by the National Science Foundation (NSF),
the InterNIC is currently run by Network Solutions and AT&T.
See also RFC.
IP (Internet Protocol) The protocol responsible for
transmitting packets of data over the Internet and routing them
to their destinations. Tagging a packet with an IP address
identifying an Internet host and transmitting it using IP is
analogous to addressing an envelope and dropping it in the mail.
IP plays the
role of post office, allowing the networks and routers involved
in the delivery process to talk to each other as the packet
finds its way to the addressee. See also TCP, TCP/IP, and UDP.
ISDN (Integrated Services Digital Network) A digital
telephone network that transmits data in digital form (1's and
0's) rather than analog form. Provided it's available in your
area, ISDN is a quick and convenient way to access
the Internet from your home or small office at speeds of up to
128 Kbps.
ISP (Internet Service Provider) A company, usually a
local one, that provides connections to the Internet for a
monthly or hourly fee.
MIME (Multipurpose Internet Mail Extensions) A protocol
for sending non-ASCII data-for example, sound, video, and
graphics over the Internet using text-based transport protocols
such as SMTP. See also POP and SMTP.
NNTP (Network News Transfer Protocol) The protocol used
to transmit Usenet messages across the Internet.
PING (Packet Internet Groper) A TCP/IP application used
to determine whether other machines are online and available.
Pinging is performed by sending an ICMP echo request waiting
for a reply. See also ICMP.
POP (Post Office Protocol) The text based protocol used
to send and retrieve
Internet e-mail messages. Unlike SMTP, which is used primarily
to transfer mail
messages between mail servers, POP provides a way for mail
programs to interact with the virtual mailboxes in which
messages wait until they are sent or retrieved. POP comes in
two flavors: POP2 and POP3. The two are related in name only
and are not compatible. See also SMTP.
PPP (Point-to-Point Protocol) The most popular protocol
for establishing
dial-up connections to the Internet. PPP is similar to but more
robust than
SLI, which lacks support for data compression, error
detection, and multiple
protocols on a single line. PPP resolves all these deficiencies
and more. See also PPTP and SLIP.
RARP (Reverse Address Resolution Protocol) The Internet
protocol that permits a physical network address (for example,
a 48-bit Ether-net address) to be translated into an IP address
by sending a request to an RARP server.
This protocol is used by diskless workstations to determine
their own IP addresses at startup. See also ARP.
RFC (Request for Comments) An online document containing
proposals, standards, and other information regarding Internet
technologies. RFCs are available by anonymous FTP from a variety
of locations, including InterNIC's own ds.internic.net. They
may also be requested by e-mail (mailserv@ds.intemic.com) or by
phone (800-444-4345).
SLIP (Serial Line Internet Protocol) A widely used but
somewhat outdated protocol for establishing dial-up connections
to the Internet. Technically speaking, SLIP is a packet-framing
protocol that defines how IP datagrams
(packets of data transmitted over the Internet using IP) are
packaged for transmission over serial data lines-for example,
over a seriallink between your modem and an Internet service
provider. See also IP, PPP, and PPTP.
SMTP (Simple Mail Transfer Protocol) The text-based TCP/IP
protocol used to exchange mail messages on the Internet. A
simplified version of the earlier MTP (Mail Transport Protocol),
SMTP defines the format and content of transactions between mail
servers. See also MIME and POP.
T1 A leased line that provides high-speed 1.544-Mbps
(megabit per second) connections to the Internet. Typically
available in large-company and university settings. Also known
as "Web Surfer's Heaven."
T3 A leased line that provides ultra-high-speed 45-Mbps
connections to the Internet.
TCP (Transmission Control Protocol) The TCP/IP protocol
that provides reliable stream delivery service to Internet
applications. Using TCP, an Internet client can open a virtual
connection to another Internet client and transmit streams of
data. Unlike its counterpart, UDP, the TCP protocol ensures
reliable delivery by retransmitting lost and corrupted data
packets. It also guarantees that an application on the receiving
end of a TCP connection will receive bits and bytes in the same
order in which they were sent. See also UDP.
TCP/IP (Transmission Control Protocol/Internet Protocol)
A suite of networking protocols that includes TCP IP UDP ARP
RARP, and ICMP, to name just a few. Often referred to as the
"the glue that binds the Internet," TCP/IP allows disjoint,
dissimilar, and spatially separated physical networks to be
joined together
to form one large virtual network, or "internet." For more
detailed discussion of TCP/IP, see the Tutor column "A
Beginner's Guide to TCP/IP" in the November 19,1996, issue of
PC Magazine.
TFTP (Trivial File Transfer Protocol) A simplified version
of FTP that lacks the authentication services FTP provides and
relies on UDP rather than TCP for data transport. TFTP is less
complex and easier to program than FTP. See also FTP.
UDP (User Datagram Protocol) The TCP/IP protocol that
allows packets of data, or datagrams, to be sent from one
Internet application to another. UDP is a "connectionless"
protocol, because, unlike TCP, it does not require the sender
and receiver to establish connection before data is transmitted.
It's considered "unreliable," because it doesn't guarantee that
datagrams will arrive in the same order they were sent, or even
that they will arrive at all. If reliability is desired, it's
up to the application using UDP to provide it. See also TCP.
URL (Uniform Resource Locator) A human-readable string
that identifies the location of a resource on the Internet
(for example, a page of HTML data or a .GIF file) and the
protocol used to retrieve it. The URL for a document published
by the World Wide Web Consortium that describes the format of
URLs is
http://www.w3.orglpub/WWW/Addressing/Addressing.html
VRML (Virtual Reality Modeling Language) The 3-D counterpart
to HTML, VRML is a
scriptlike language that permits rich 3-D scenes to be
described in simple text files and displayed in VRML-capable
Web browsers. VRML solves the problem of the high bandwidth
required to transmit bitmapped scenes by minimizing the flow
of information from the Web server to the browser and allowing
the browser to render the scene-and thus do the bulk of the
work required to display the
scene-locally. See also HTML.
WWW (World Wide Web) A virtual world formed by Internet
HTTP servers containing
richly formatted pages that can be downloaded upon request to
browsers such as
Netscape Navigator and Microsoft Internet Explorer. It is more
commonly known as
"the Web." It was the creation of this network in 1994 (and the
proliferation of
browsers that followed soon after) that made Internet a
household word. See also HTML, HTTP, and VRML.
Jeff Prosise is a contributing editor PC Magazine.
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MAY 27,1997