Term
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Definition
| Describes any system based on discontinuous data or events; in the case of computers, it refers to communications signals or information represented in a two-state (binary) way using electronic or electromagnetic signals. Each 0 and 1 signal represents a bit. |
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Term
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Definition
| Continuously varying in strength and/or quality- fluctuating, evolving, or continually changing. |
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Term
| WAN (wide area network) (pg. 316) |
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Definition
| Communications network that covers a wide geographic area, such as a country or the world |
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Term
| MAN (metropolitan area network) (pg. 317) |
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Definition
| Communications network covering a city or a suburb |
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Term
| Client-server network (pg. 318) |
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Definition
| Consists of clients, which are microcomputers that request data, and servers, which are used to supply data |
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Term
| Peer-to-peer network (pg. 319) |
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Definition
| All microcomputers on the network communicate directly with one another without relying on a server. |
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Term
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Definition
| An organization’s internal private network that uses the infrastructure and standards of the internet and the web |
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Term
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Definition
| Private intranets that connect not only internal personnel but also selected suppliers and other strategic parties |
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Term
| VPN (virtual private network) (pg. 320) |
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Definition
| Private networks that use a public network (usually the internet) to connect remote sites |
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Term
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Definition
| A mainframe or midsize central computer that controls the network |
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Term
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Definition
| Any device that is attached to a network- for example, a microcomputer, terminal, storage device, or printer |
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Term
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Definition
| A common connection point for devices in a network- a place of convergence where data arrives from one or more directions and is forwarded out in one or more other directions. |
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Term
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Definition
| A device that connects computers to a network |
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Term
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Definition
| An interface used to connect the same types of networks |
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Term
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Definition
| An interface permitting communication between dissimilar networks |
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Term
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Definition
| A special computer that directs communicating messages where several network are connected together |
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Term
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Definition
| The logical layout, or shape, of a network |
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Term
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Definition
| All nodes are connected to a single wire or cable, the bus, which has two endpoints. Each communication device on the network transmits electronic messages to other devices. |
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Term
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Definition
| All microcomputers and other communications devices are connected in a continuous loop. |
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Term
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Definition
| All microcomputers and other communications devices are directly connected to a central server |
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Term
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Definition
| A 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 |
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Term
| Twisted-pair wire (pg. 325) |
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Definition
| Consists of two strands of insulated copper wire, twisted around each other. This twisted-pair configuration (compared to straight wire) somewhat reduces interference (called “crosstalk”) from electrical fields |
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Term
| Coaxial cable (pg. 325) (Commonly called “co-ax”) |
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Definition
| A high-frequency transmission cable that consists of insulated copper wire wrapped in a solid or braided metal shield and then in an external plastic cover |
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Term
| Fiber-optic cable (pg. 325) |
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Definition
| Consists of dozens or hundreds of thin strands of glass or plastic that transmit pulsating beams of light rather than electricity |
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Term
| Wireless Application protocol (WAP) (pg. 329) |
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Definition
| Designed to link nearly all mobile devices to your telecommunications carrier’s wireless network and content providers |
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Term
| Infrared wireless transmission (pg. 330) |
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Definition
| Sends data signals using infrared-light waves at a frequency too low (1-4 megabits per second) for human eyes to receive and interpret |
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Term
| Global Positioning System (GPS) (pg. 334) |
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Definition
| Consists of 24 earth-orbiting satellites continuously transmitting timed radio signals that can be used to identify earth locations |
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Term
| Digital wireless service (pg. 338) |
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Definition
| Supports digital cellphones and personal digital assistants- uses a network of cell towers to send voice communications and data over the airwaves in digital form. |
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Term
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Definition
| Short-range wireless digital standard aimed at linking cellphones, PDAs, computers, and peripherals up to distanced of 30 feet |
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Term
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Definition
| Would have a typical range of 32 feet and a maximum data rate of 480 megabits per second |
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Term
| Denial of service (DoS) attack (pg. 345) |
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Definition
| Consists of making repeated requests of a computer system or network, thereby overloading it and denying legitimate users access to it |
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Term
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Definition
| A program that copies itself repeatedly into a computer’s memory or onto a disk drive |
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Term
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Definition
| (1) Computer enthusiasts, people who enjoy learning programming languages and computer systems, but also (2) People who gain unauthorized access to computers or networks, often just for the challenge of it |
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Term
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Definition
| Malicious hackers, people who break into computers for malicious purposes |
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Term
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Definition
| A system of hardware and/or software that protects a computer or a network from intruders. |
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Term
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Definition
| The process of altering readable data into unreadable form to prevent unauthorized access |
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Term
| Contrast digital and analog data. (pgs. 311-312) |
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Definition
Digital: Describes any system based on discontinuous data or events; in the case of computers, it refers to communications signals or information represented in a two-state (binary) way using electronic or electromagnetic signals. Each 0 and 1 signal represents a bit.
Analog: Continuously varying in strength and/or quality- fluctuating, evolving, or continually changing. |
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Term
| Describe the benefits of using a network. (pg. 316) |
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Definition
Sharing of peripheral devices
Sharing of programs and data
Better communications
Security of information
Access to databases |
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Term
| Contrast intranets, extranets, and virtual private networks (VPNs). (pgs. 319-320) |
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Definition
Intranet: For internal use only
Extranet: For certain outsiders
Virtual private network: Uses a public network to connect to remote sites |
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Term
| Identify the major components of a network. (pgs. 320-322) |
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Definition
Wired and/or wireless connections
Hosts and nodes
Packets
Protocols
Network linking devices: hubs, switches, bridges, gateways, routers, and backbones |
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Term
| What are the three basic network topologies? (pg. 322) |
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Definition
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Term
| What are the main characteristics of each of the three types of wired communications media in reference to wires and cables? (pgs. 325-326) |
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Definition
Twisted-pair wire: Consists of two pairs of insulated copper wire, twisted around each other
Coaxial cable: High-frequency transmission cable that consists of insulated copper wire wrapped in a solid or braided metal shield and then in an external plastic cover
Fiber-optic cable: Consists of dozens or hundreds of ting strands of glass or plastic that transmit pulsating beams of light rather than electricity |
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Term
| What is the significance of bandwidth? (pg. 329) |
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Definition
| It is the range, or band, of frequencies that a transmission medium can carry in a given period of time. |
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Term
| What are the main characteristics of each of the four types of wireless communications media? (pgs. 330-333) |
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Definition
Infrared transmission: Sends data signals using infrared-light waves at a frequency too low (1-4 megabits per second) for human eyes to receive and interpret
Broadcast radio: A wireless transmission medium that sends data over long distances at up to 2 megabits per second- between regions, states, or countries
Microwave radio: Transmits voice and data at 45 megabits per second through the atmosphere as super high-frequency radio waves called microwaves which vibrate at 1 gigahertz (1 billion hertz) per second or higher |
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Term
| How does a GPS work? (pg. 334) |
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Definition
| Consists of 24 earth orbiting satellites continuously transmitting timed radio signals that can be used to identify earth locations |
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Term
| Describe the features of and upgrades available for third generation (3G) wireless digital services. (pg. 339) |
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Definition
EV-DA (Evolution Data Only)
UMTS: (Universal Mobile Communications Systems) |
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Term
| What are the three types of short range wireless two-way communication technologies? (pg. 340) |
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Definition
Local area networks: Range 50-150 feet
Personal area networks: Range 30-32 feet
Home automation networks: Range 100-250 feet |
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Term
| What are the four varieties of Wi-Fi standards? (pg. 340) |
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Definition
Wi-Fi a
Wi-Fi b
Wi-Fi g
Wi-Fi n |
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Term
| List four cyberthreats. (pg. 345) |
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Definition
Denial-of-service attack
Worms
Viruses
Trojan horses |
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Term
| What are five standards that help secure computer systems? (pgs. 350-353) |
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Definition
Antivirus software
Firewalls
Passwords
Biometric authentication
Encryption |
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Term
| Describe advances in photonics that could increase the speed of delivery through fiber optic lines. (pgs. 355-356) |
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Definition
| The development of the optical amplifier |
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