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access controls Methods used to control access to the Internet and internal networks.

ACL Access Control Lists are databases of permissions assigned to users and groups

animated image A GIF file that moves on the screen is an animated image.

ASCII The American Standard Code for Information Interchange uses an 8-bit number to represent an English alphanumeric character.

asymmetric system Encryption system where key pairs (a public and a private key) are generated. The public key encrypts and the private key decrypts the messages.

auditing Keeping track of activity both from the outside (Internet/extranet) or from inside (a company intranet) to reveal potential security risks.

authentication The process of determining if someone is who he or she claims to be before granting or denying network access. Usernames and passwords are forms of access control.

B2B An abbreviation often used for business-to-business E-commerce transactions.

banner An advertisement, usually wider than high, placed on a Web page that links to another page.

banner exchange The mutual sharing of Web space among E-commerce businesses for banner advertisements that provides free advertising.

binary A mathematical system that has only 2 values (1 or 0) for each number. In computer terminology, each

binary number is called a bit.

bit The basic building block of data, usually described as a 0 or 1.

bookmark An entry in a list of favorite sites that is maintained by your browser.

bps Bits per second. Used to measure the data rate of a transmission medium.

bridge A network hardware device that connects network segments into one logical network. Bridges also have functions that control broadcast traffic on a network.

broadband Type of data transmission in which a single medium (wire) can carry several channels at once.

broadcast storm A self-perpetuating broadcast cycle on a network. Broadcast storms completely dominate network traffic and shut down a network. A bridge using the Spanning Tree Algorithm can prevent a broadcast storm.

browser A software application used to locate and display Web pages. Netscape Communicator and Microsoft Internet Explorer are the most popular graphical browsers. They interpret HTML codes to display graphics as well as text and can support programming languages like JavaScript to create interactive Web pages. Many

browsers can also present full multimedia sound and video using small applications called plug-ins.

buffer Temporary memory space used for constantly changing data.

business-to-consumer E-commerce transactions between a business and the consumer.

byte A combination of 8 bits, used, among other things, to represent characters such as letters of the alphabet or numbers.

C++ An object-oriented superset of the C programming language.

CA Certificate Authority is a trusted third party, which after exhaustive background checks, issues digital certificates.

cable modem A device that enables you to access the Internet through your cable TV system.

cache A special memory space used to store frequently accessed information.

cache server Servers that store frequently used Web pages and their components to speed client Web page access.

certificate servers Servers that manage the issuance, revocation, and renewal of digital certificates.

certificates A digital identification, verifying a secure server’s identity to the client and verifying the client’s identity to the server.

CGI Common Gateway Interface is not a programming language, but an interface that defines how programs can interact on the Web.

checksum A calculation result that is compared to an expected result. Computers use checksums for error control.

cladding Reflective covering that surrounds the glass core of a fiber-optic cable.

class In a style sheet, categories into which you can divide HTML elements in order to assign styles to them more selectively.

client The requestor of server services.

coax Same as coaxial.

coaxial Cabling (also called coax) that consists of one solid copper core which is surrounded by insulation, a braided metal shielding, and a jacket. The inner insulation ensures that no signals can pass from the copper core and no signals from outside the insulation can pass into the copper core. There are thick and thin types of coaxial cable.

COM Component Object Model is a Microsoft specification that defines standards for interaction among programs, including application software and operating systems.

compiled programming language A programming language in which source code converts in one fell swoop into machine code to create an executable file.

cookies Text files of which one part is loaded onto the hard disk of a client computer and another part resides on the visited server in a user profile database. Each cookie contains a unique identifier and may contain confidential information such as the name of the visitor, authentication, credit card numbers, and online shopping habits.

denial of service Deliberate attacks to breach security by disabling a network rather than stealing critical data.

digital signatures An electronic means of verifying a user’s identity.

DISA The Data Interchange Standards Association is a not-for-profit organization that concentrates on E-commerce related standards and issues (including EDI).

ECSB The Electronic Commerce Standards Board is a CompTIA advisory board that addresses business-to-business E-commerce standards and issues.

EDI The Electronic Data Interchange is a standard for exchanging information electronically between businesses.

e-mail marketing A method of attracting customers by sending large volume bulk e-mail messages to potential customers.

EMI Electromagnetic Interference is a byproduct of electricity moving through wire.

encryption Transforms data into a form unreadable to everyone except those that have the correct algorithm or key to unlock the data.

Ethernet Ethernet is a local area networkLAN system developed by the Xerox Corporation in 1976. The IEEE Ethernet/802.3 standard for the 10- or 100-Mbps transmission for hardware and data packet construction specifications was derived from Ethernet.

extranet A collection of intranets.

fiber-optic cable A cable that uses glass strands and light pulses instead of electrical signals to transmit data.

firewall A security system that protects an organization’s network against internal and external threats.

frame relay Packet-switching technology based on X.25 with less error control and faster speeds.

FTP File Transfer Protocol—an Internet protocol used for transferring files among diverse computers.

FTP server Servers used for sending out and receiving FTP file transfers.

gateway Hardware or software setup that translates between two dissimilar protocols and performs conversion service for data.

Gbps The abbreviation for Gigabits Per Second. Gbps is a measurement of data transfer speed on a network, in multiples of 1,073,741,824 (230) bits.

gigabyte A billion bytes.

GII The Global Information Infrastructure is a group started by the Ziff-Davis publishing company to create the Standard for Internet Commerce.

Gopher Once the most popular client/server search engine on the Internet, Gopher has been almost completely replaced by modern search engines like Yahoo and AltaVista.

Gopher server Servers used to display distributed text files by listing them in menus.

graphical interface A computer interface designed with a visual metaphor to help users intuitively know how to perform operations.

hacker An intrusive individual who is interested in gaining knowledge about computer systems and possibly using this knowledge for pranks.

home page The initial page that a user sees in a browser or a Web page that people create to publish information about themselves.

hop The path that data travel from one router to the next.

HPC Handheld PC. A computer that fits in the palm of your hand.

HTML HyperText Markup Language. A protocol used to package and transfer Web pages.

HTTP HyperText Transfer Protocol. A computer language used for creating Web pages.

hub Hardware that splits a network signal and connects networks together.

ICANN Internet Corporation for Assigned Names and Numbers. A non-profit corporation that has responsibility for the accreditation of new domain registrars for the top-level domains of .com, .net, and .org.

IIS Internet Information Server is a popular Web server made by Microsoft.

IMAP Internet Message Access Protocol retrieves e-mail messages from an e-mail server. The latest version is

IMAP4, which is similar to POP3 except that it supports several enhancements.

Internet A “network of networks” connecting millions of computers in local, regional, national networks.

internetwork A collection of LANs connected via routers.

InterNIC A cooperative activity between the U.S. Government and Network Solutions, Inc. For many years, it was the sole provider of domain name registration services for .com, .net, and .org top-level domains.

intranet The portion of a network that is not accessible to the general public. The intranet is usually separated from the extranet and Internet by a firewall and is used for internal communications within a business.

intrusion detection Tracking and recording any suspicious activity on a network.

IP address A 32-bit number represented as four decimal numbers separated by periods. The first 1, 2, or 3 bytes of the IP address identify the network to which the host is connected; the remaining bits identify the host itself.

ISDN Integrated Services Digital Network is a high-speed digital communications network, which evolved from existing telephone services.

ISDN terminal adapter Integrated Services Digital Network terminal adapters are devices that accept digital signals from a telephone line and translate them into digital data that is recognizable to a computer.

ISP Internet Service Provider is a company or organization that provides Internet access to businesses, large and small organizations, and individual users.

jitter Jitter is an annoying and perceptible variation in the time it takes various workstations to respond to messages.

K A kilo or kilobyte is 1,024 bytes of data storage.

Kbps Kilobits per second.

LAN Local Area Network is a small network that covers a small area such as an office, one floor of a building, or one department of a large organization.

LDAP Lightweight Directory Access Protocol is a client server service for search databases using ordinary text queries.

line protocol Enables a local computer to connect to a modem on a remote computer and connect the two devices.

link A spot in a Web page that transfers you to another Web page.

local computer The computer that can be accessed directly rather than by means of a communications line.

local loop Connects the subscriber wiring at a business or residence to the telephone company’s local central office.

loop-back This special IP address (127.0.0.1) will cause the PING utility to detect a host computer’s own NIC.

LPR Line Printer is a client/server protocol for sending and receiving print documents across a TCP/IP network.

M Mega or megabyte is 1,048,576 bytes of data storage.

MAC Media Access Control manages access to the physical network, delimits datagrams, and handles error control.

mail server Servers that manage e-mail.

mailing list A list of users who all wish to receive a common set of mail.

MAN Metropolitan Area Network is a small WAN that covers a city or metropolitan area.

Mb Abbreviation for Megabit (1,048,576 bits (230)), sometimes referred to as 1 million bits.

Mbps Abbreviation for Megabits per second.

Megabit A Megabit is a measurement of storage capacity equal to about 1 million bits or 1,048,576 bits (230).

merchant account An account with a banking institution needed to process credit card sales.

META An HTML tag used to insert hidden keywords into a Web page, so search engines will display your page when one or more of the keywords is searched for.

MIME Multipurpose Internet Mail Extensions is a specification for formatting non-ASCII messages for transmission over the Internet. Many e-mail client applications support MIME because it enables them to send and receive graphics, video, and audio files through the Internet mail system.

modem Originally referred to a device that MOdulated and DEModulated digital information across telephone lines. Now used to describe a wide variety of data interfaces for computers.

multiple logon failures A number of unsuccessful attempts to access a network, which can indicate a possible hacker attack.

multiplexer A device that can divide a single T1 or E1 connection into data lines and voice lines.

NAP Network Access Point is a large exchange point for Internet traffic. Established by the NSF. Navigator Netscape’s first browser.

NetBEUI NetBIOS Enhanced User Interface is a simple fast network protocol that is not routable.

Netscape Enterprise Server A popular Web server made by Netscape.

NETSTAT A command line utility that generates datagram statistics sorted by protocols used.

network adapter Another name for network interface card (NIC).

network protocol TCP/IP, IPX/SPX, NetBEUI, AsyNetBEUI, are the usual network communications protocols used to access remote Internet network servers.

news server A server that maintains a database of newsgroups.

newsgroup A collection of messages with a related theme, located on a news server.

NIC A Network Interface Card is an expansion card or other device that provides network access to a computer or other device, such as a printer. NICs mediate between the computer and the physical media, such as cabling over which transmissions travel.

NNTP Network News Transfer Protocol provides services for special interest group forums to organize posted discussions in hierarchical threads.

NOC Network Operations Center—the main operations center and/or data center.

node A device, such as a client computer, server, or shared printer that connects to the network and communicates with other network devices.

NSFNet Funded by the National Science Foundation, this network’s main constituents were universities, government agencies, and organizations involved in research. ARPANet was its foundation and it later evolved into the Internet.

NSP Network Service Providers are companies such as PSINet and UUNET which maintain the nationwide communications links that make up the Internet backbone.

octet A group of eight. In binary language an octet is 8 bits of information. Another term for 8 bits is a byte. In decimal format, a byte has a value range of 0 to 255.

one-way hash function An algorithm that converts text into a fixed-length string of digits which, in turn, is encrypted with a private key to create a digital signature that authenticates the sender.

online Logged onto the internet.

OSPF Open Shortest Path First is a routing protocol that minimizes broadcast transmissions between routers supports variable-length subnetting.

packet A unit of transmission data with fixed size and header information about source, destination, and data assembly.

packet filtering Inspecting packets to determine whether or not to grant or deny access to a network.

packet switching A networking technology that divides a message into packets, each labeled with a destination address. The packets travel through a network and are reassembled at the destination.

parameters Properties represented by user-settable variables.

PCT Private Communication Technology is a protocol that separates authentication from encryption and allows applications to use authentication that is stronger than the 40-bit key limit for encryption allowed by the U.S. government for export.

PGP Pretty Good Privacy is an encryption method based on the asymmetric key system.

physical address The hexadecimal number associated with a Network Interface Card (NIC).

PING A command line utility used to check network connections.

PING:flood Echo requests to an IP address (PINGs) transmit to a system in overwhelming numbers. The system under attack cannot handle the bombardment and crashes.

POP Post Office Protocol is a protocol used for incoming messages.

port An interface through which data are transferred between a computer and other devices, such as a network or another computer. It appears to the processing computer as an address in memory to send and receive data.

port number The number associated with an application.

portal An all-purpose link to the Web. It contains news, sports, weather, electronic mail and more.

POTS Plain Old Telephone System refers to the public telephone system. Public phone lines are used to connect a local computer to a network computer using the DUN feature in Windows.

PPP Point-to-Point Protocol is a protocol that controls communications from a user’s residence over telephone lines to an ISP.

PPTP Point-to-Point Tunneling Protocol is a more secure version of PPP. This connection supports the encryption and compression of all transmitted data. To use PPTP requires connection to a remote tunnel server. Once connected PPTP supports all the same network protocols as PPP (TCP/IP, IPX/SPX, NetBEUI, etc.) to access the network.

private key system A symmetric encryption system that uses a single key which both the sender and the recipient use to encrypt and decrypt messages.

proxy server A server located between a client application and remote servers which provides, among other things, security into and out of your network.

proxy server cache A quickly accessible storage area for Web pages that are frequently viewed with a Web browser.

PSTN Public Switched Telephone Network is the telephone system that carries analog voice data.

public key system See asymmetric key system

pull The technology usually used on the Internet, where the user requests data from a Web server.

push A technology that sends data to a user, even if that data was not specifically requested. Used to customize and filter Web page content.

PWS Personal Web Server is a popular Web server made by the Microsoft for PCs running Windows 95/98.

query An inquiry for information from a database.

RAS Remote Access Server. A Microsoft communications server.

remote Any files, devices, or other resources not connected directly to your workstation. Resources connected directly to a workstation are local.

Remote Access Server A network server that enables you to log into a Windows NT-based LAN using a modem.

remote computer The computer that an operator accesses by way of a modem.

repeater Repeaters are simple hardware devices that receive digital information, regenerate the signal, and pass it along.

RIP Routing Information Protocol is a common service provided by routers that use broadcasts to communicate with other routers, gathering path and host ID information.

root servers Primary servers at the foundation of DNS.

router Any device having multiple NICs that filter, forward, and redirect network traffic.

S/MIME Secure MIME is a protocol used in secure e-mail exchanges.

screening router Programmable routers that follow a set of rules to inspect packets and permit or deny access to a network based on those rules.

SDSL Symmetric Digital Subscriber Line. A European DSL standard that supports symmetric traffic, equivalent data transmission rates in each direction, of up to 3 Mbps

search engines Web sites that perform keyword searches of Web pages and provide a convenient location for users to find products and services.

segment Connected devices not separated by a bridge or a router.

server A computer or program on the Internet or other network that responds to commands from a client.

SET Secure Electronic Transaction protocol provides strong encryption and direct data transfers to financial institutions.

S-HTTP Secure HyperText Transfer Protocol encrypts individual messages for transmission across the

unsecured Internet.

SIG Special Interest Group is any group of people that meet in person or via discussion groups over the Internet to exchange ideas and information about a single topic.

signature file Anti-virus software programs rely on virus signature files to identify new and existing computer viruses. Makers of the anti-virus software frequently update virus signature files.

SLIP Serial Line Internet Protocol is a Unix protocol.

SMTP Simple Mail Transport Protocol is a protocol used for outgoing messages and communications between mail servers.

smurf Another name for a PING flood attack.

sockets A software object that connects applications to a network protocol for sending and receiving TCP/IP messages.

source-route bridge Connect token-ring networks, a network technology developed by IBM.

spam Another term for e-mail marketing, spam is often blocked by ISPs.

spamming floods An e-mail attack that transmits unsolicited data in quantities that can overwhelm a mail server and disable it.

Spanning Tree Algorithm A standard that establishes protocols for network bridges and is responsible for controlling broadcast storms.

spoofing A technique used by hackers to trick their way through a firewall into a network by changing the information in a packet to look like a friendly packet.

SQL Server A Microsoft database management system.

SSL Secure Sockets Layer is a protocol that creates a secure connection, or channel, over which all data between a Web client and a secure Web server are encrypted.

STP Shielded Twisted-Pair cable.

streaming media A data transfer system that allows the media to be accessed while it is still being transferred.

subnet A local area network (LAN) that has been divided into separate network segments. Routers can divide LANs into subnets and transfer data among subnets. All devices on a subnet can communicate without routing datagrams.

subnet mask The subnet mask, or address mask, determines which part of the 32-bit binary IP address is the network ID information and which part is the host ID information.

supernet A process where bits are borrowed from network ID bits and used to combine networks. This process is used to combine multiple Class C networks into virtual class B networks.

switch A hub with bridge functionality for each port.

SYN flood A SYN is a flag in a packet header. The SYN flag is a request to open a port in a firewall. When a hacker sends hundreds or thousands of these to a firewall in a few minutes or seconds, it is a SYN flood attack designed to create a denial of service and bring down the target network.

T1 High-speed carrier with 24 64-Kbps channels combined into one 1.5-Mbps connection.

T3 High-speed carrier that transmits at 45-Mbps connections.

Telnet A command-line utility for remote connectivity across TCP/IP.

Telnet server Servers which permit a computer to act as a terminal for another computer.

terminal emulation Software designed to make a PC mimic the behavior of a particular monitor/keyboard model associated with mainframe computers.

thicknet A thick type of coaxial cable that is somewhat rigid and measures about 0.5 inch in diameter with a thick copper core.

thinnet A thin type of coaxial cable that is flexible and measures about 0.25 inch thick in diameter.

throughput The rate at which data are transferred on a network and measured as the number of transmitted bits per second (bps).

TLS Transport Layer Security is a Microsoft security protocol that incorporates both SSL and PCT into one standard that supports both certificates and password authentication.

top-level servers The second tier of DNS, these computers store registration data about domain names.

TRACERT A command line utility that generates datagram path information on an internetwork.

translational bridge Connect different types of networks, such as TCP/IP and token-ring networks.

UDP User Datagram Protocol is available as an alternative protocol to TCP. UDP is fast but contains no error checking or delivery confirmation services.

UN/EDIFACT One of two EDI standards, UN/EDIFACT is used by businesses outside the United States.

Unicode A standard that assigns numbers to language characters, Unicode uses 16 bits of code per character, thus supporting 65,000 characters. Due to its support for all languages (not just English), it is expected to replace ASCII code as the standard for displaying characters.

up-link Usually refers to sending data to a satellite receiver.

URL Uniform Resource Locator is an address that points to a document on the World Wide Web.

Usenet The most popular newsgroup system.

UTP Unshielded Twisted-Pair cable.

variable-length subnetting A system for creating internal IP addressing that allows use of any class address while registering a single subnet with InterNIC.

viruses Viruses are small, often destructive, programs that may be disguised as part of a harmless file, game, utility, or e-mail attachment.

VPNs A Virtual Private Network creates encrypted private communication channels over the public Internet.

WAN Wide Area Network is a collection of LANs or internetworks that covers a large geographic area such as multiple branches of a large company.

Web browser A program used to display Web pages.

Web page A page displayable in a Web browser, containing hot links, text, graphics, video, audio and more.

Web server A server that provides data in the form of Web pages.

WebTV A system that displays Internet content on your TV screen.

WINS Windows Internet Naming Service is a Microsoft solution for NetBIOS/IP address name resolution.

Winsock This API enables Windows programs to communicate with other computers by using the TCP/IP protocol. Winsock is designed upon the socket’s API in Unix. Windows 98 and Windows NT use the Dynamic Link Library (DLL) called WINSOCK.DLL to read and write data to and from TCP/IP-supported applications.

WWW World Wide Web is a subset of the Internet characterized by easy-to-navigate Web pages.

X.25 Packet-switching technology with robust error control and maximum connection speeds of 64 Kbps.

X12 The EDI standard used by businesses within the U.S.

XML Extensible Markup Language is a new markup language similar to HTML but with a richer feature set.