3.3+Networks


 * 3.3 Networks**

This topic addresses the role of networks in a range of different scenarios. Almost all businesses, institutions and organizations, and an increasing number of households, are linked by networks. The increasing use of networks raises a range of social impacts and ethical issues such as unauthorized access, intrusive software (viruses, worms and Trojan horses), spam, phishing, pharming, spoofing and identity theft. Students are expected to discuss possible solutions and evaluate their effectiveness.

Read Tomorrow's Technology & You, p. 270 - 307. You will find many definitions for the the vocabulary listed below throughout the reading and in the book's glossary.

Define each of the following and include a picture where possible:
 * = **Vocabulary** ||= **Definition** ||
 * **Client Server** || Client programs in desktop computers send information requests through a network to server databases on mainframes, mini-computers, or desktop computers; the servers process queries and send the requested data back to the client. ||
 * **Host server** || Computer that provides services to multiple users of other computers. ||
 * **Mainframe** || Expensive, room-sized computer, used mostly for large computing job, most have the ability to run (or host) multiple operating systems. ||
 * **Supercomputers** || A super-fast, super-powerful and super-expensive computer used for applications that demand maximum power. ||
 * **Network operating systems** || Server operating system software for a local-area network. ||
 * **Network utility software** || Analyze the computer's network connectivity, configure network settings, check data transfer or log events. ||
 * **Ethernet** || A system for connecting a number of computer to form a local area networks. ||
 * **Optical fibre** || Used in transmitting information from one place to another by sending pulses of light. The light forms an electromagnetic carrier wave that is modulated to carry information. ||
 * **Cable** || Used to connect one network device to other or to connect two or more computers to share printer, scanner etc. ||
 * **Wireless fidelity (WiFi)** || A popular wireless LAN technology that allows multiple computers to connect to a LAN through a base station up to 150 feet away.

Allow electronic devices (personal computer, video game console, smartphone, etc.) to connect to the Internet within the range of the wireless network access point. ||
 * **World wide interoperability for microwave access (WiMax)** || A wireless alternative to cable or DSL device. ||
 * **Bluetooth** || A standard for the short-range wireless interconnection of cellular phones, computers, and other electronic devices. ||
 * **Microwave** || An electromagnetic wave with a wavelength shorter than that of a normal radio wave but longer than those of infrared radiation that is used for transmitting information. ||
 * **Virtual private network (VPN)** || A network that uses encryption software to create secure "tunnels" through the public Internet or between intranets.

A method an organization can use to set up an extranet.

Use Internet to provide remote offices or traveling users access to a central organizational network. ||
 * **Local area network (LAN)** || Multiple personal computers connected on a network. ||
 * **Wide area network (WAN)*** || A network that extends over a long distance. Each network site is a node on the network. ||
 * **Virtual LAN (VLAN)*** || Allows a physical network to be partitioned into multiple logical networks. Only stations within the same group can communicate with each other. Stations on a logical network can belong to one or more groups. ||
 * **Wireless LAN (WLAN)** || Uses high frequency radio waves to transmit and receive data over distances of a few hundred feet instead of a cable or wire. ||
 * **Home network** || A residential local area network. It is used for communication between digital devices typically deployed in the home, usually a small number of personal computers and accessories, such as printers and mobile computing devices. ||
 * **Internet** || A global interconnected network of thousands of networks linking academic, research, government, and commercial institutions, and other organizations and individuals. Also known as the Net. ||
 * **Intranet** || A self-contained intraorganizational network that is designed using the same technology as the Internet. ||
 * **Extranet*** || A corporation's intranet that is opened up to work with strategic partners and customers. ||
 * **Router** || Programs or devices that decide how to route Internet transmissions. ||
 * **Switch** || Hardware that decides how to route Internet transmissions. Switches are similar to software routers, but faster and less flexible. ||
 * **Hub** || Devices that allow nodes on a local area network to communicate, though only a single message at a time can move across the network. ||
 * **Peer-to-peer (P2P)** || A LAN model that allows every computer on the network to be both client and server. ||
 * **Cloud computing** || A type of grid computing in which resources (storage, applications, data, and more) are distributed across the Internet rather than confined to a single machine. Resources seem to be coming from "the cloud" (the Internet) rather than from a particular computer. ||
 * **Grid computing*** || A form of distributed computing in which not files, but processing power is shared between networked computers. ||
 * **Distributed processing*** || Integrating all kinds of computers, from mainframes to PCs, into a single, seamless system. ||
 * **Storage technologies** || The techniques, equipment, and organization for providing the memory capability required by computers in order to store instructions and data for processing at high electronic speeds. ||