CSC Chapter 6

hacker

A hacker can be either (1) a computer enthusiast, a person who enjoys learning programming languages and computer systems; or (2) a person who gains unauthorized access to computers or networks, often just for the challenge of it

botnet

A network of computers compromised by means of a Trojan horse that plants instructions within each PC to wait for commands from the person controlling that network

trojan horse

A program that pretends to be a useful program, such as a game or screen saver, but that carries viruses, or destructive instructions

GPS (Global Positioning System)

A series of earth orbiting satellites continuously transmitting timed radio signals that can be used to identify earth locations.

bandwidth

Also called band; range of frequencies that a transmission medium can carry in a given period of time and thus a measure of the amount of information that can be delivered. The bandwidth is the difference between the lowest and the highest frequencies transmitted. For analog signals, bandwidth is expressed in hertz (Hz), or cycles per second. For digital signals, bandwidth is expressed in bits per second (bps)

denial of service attack (DOS)

Also called distributed denial of service (DDoS) attack; Form of technological assault that consists of making repeated fraudulent requests of a computer system or network, thereby overloading it. The assault may come from a single computer or from hundreds or thousands of computers that have been taken over by those intending harm.

zombie

Also known as a drone. A computer taken over covertly and programmed to respond to instructions sent remotely, often by instant-messaging channels.

Intranet

An organizations internal private network that use the infrastructure and standards of the internet and the web

node

Any device that is attached to a network.

broadband

Bandwidth characterized by very high speed. Transmission speeds are 1 megabit per second to as high (for super-broadband and ultra-broadband) as 100 megabits per second.

fiber-optic cable

Cable that consists of dozens or hundreds of thin strands of glass or plastic that transmit pulsating beams of light rather than electricity.

coxial cable

Commonly called "co-ax"; insulated copper wire wrapped in a solid or braided metal shield and then in an external plastic cover.

local area network

Communications network that connects computers and devices in a limited geographic area, such as one office, one building, or a group of buildings close together

digital

Communications signals or information represented in a two-state (binary) way using electronic or electromagnetic signals.

analog

Continuous and varying in strength and/or quality. An analog signal is a continuous electrical signal with such variation.

ethernet

LAN technology that can be used with almost any kind of computer and that describes how data can be sent in packets in between computers and other networked devices usually in close proximity.

client-server network

Local area network that consists of clients, which are microcomputers that request data, and servers, which are computers used to supply data.

communications satellite

Microwave relay station in orbit around the earth.

extranet

Private intranet that connects not only internal personnel but also selected suppliers and other strategic parties.

virtual private network

Private network that uses a public network, usually the internet, to connect remote sites.

worm

Program that repeatedly copies itself into a computer's memory or onto a disk drive until no space is left

bluetooth

Short-range wireless digital standard aimed at linking cellphones, PDAs, computers, and peripherals.

router

Special computer that directs communicating messages when several networks are connected together.

firewall

System of hardware and/or software that protects a computer or a network from intruders. Always-on internet connections such as cable modem and DSL, as well as some wireless devices, are particularly susceptible to unauthorized intrusion and so need a firewall.

backbone

The main highway—including gateways, routers, and other communications equipment—that connects all computer networks in an organization.

encryption

The process of using powerful mathematical concepts to create coded messages that are difficult or impossible to read. To send a message in disguised, unreadable form, you would encrypt that message into cybertext, and your colleague receiving it would then decrypt it, using an encryption key —a formula for encrypting and decrypting a coded message

identity theft

crime in which thieves hijack a person's name and identity and use his or her good credit rating to get cash or buy things.

modem

device that converts digital signals into a representation of analog form (modulation) to send over phone lines. A receiving modem then converts the analog signal back to a digital signal

protocol

set of conventions governing the exchange of data between hardware and/or software components in a communications network

network

system of interconnected computers, telephones, or other communications devices that can communicate with one another and share applications and data.