Computing in the Modern World Unit 4 Networks

GPS: BCS-CMW-8. Students will demonstrate knowledge of basic components of computer networks.

Network A collection of computers and devices connected together

Reasons Businesses Use a Network Facilitate communications Share hardware Share data & information Share software Transfer funds

Advantages of Networking Facilitating Communications-email, IM, chat rooms, blogs, etc. Sharing hardware-save money Sharing data & information-access to database for customers Sharing software-save money Transferring funds-payroll, make purchases on the Internet

Difference: the area of coverage Types of networks Local area network (LAN) Wireless local area network (WLAN) Metropolitan area network (MAN) Wide area network (WAN) Difference: the area of coverage

LAN Limited geographical area Home School computer lab Office building

WLAN LAN with no physical wires Usually communicates with a wired LAN

MAN High- speed network that connects LANs in a metropolitan area such as a city or town and handles the bulk of communications activity across that region. Regulated by local or state government Provided by telephone companies, cable television operators, and other organizations

WAN Covers a large geographic area ( such as a city, country, or the world) Combines many types of media such as telephone lines, cables, and radio waves What is the world’s largest WAN?

Network Architectures Design of computers, devices, and media in a network Two Categories Client/server Peer-to-peer

Client/Server Server-host computer Clients Controls access to hardware, software, and other resources Provides central storage area Clients Other computers and devices on the network that rely on the server for resources EX. Server stores database of customers, Client access database

Client/Server EX. Server stores database of customers, Client access database 10 or more computers

Peer-to-Peer Network Simple, inexpensive Less than 10 computers Equal responsibilities and capabilities

Internet Peer-to-Peer (P2P Users access each others hard disks and exchange files directly over the Internet Examples: Limewire BitTorrent Gnutella Kazaa

Network Topologies Layout of the computers and devices in a communications network. Three most common: Bus Ring Star

Bus Network Single central cable, to which all computers and other devices connect

Ring Network A cable forms a closed loop (ring) with all computers and devices arranged along the ring

Star Network All of the computers and devices ( nodes) on the network connect to a central device, thus forming a star

Intranet Internal network that uses Internet technologies Make company information accessible to employees Examples: telephone directories, event calendars, procedure manuals, employee benefits information, and job postings