Computing in the Modern World

Unit 4

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

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 areaHomeSchool computer labOffice

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 CategoriesClient/serverPeer-to-peer

Client/Server

Server-host computerControls access to hardware, software, and

other resourcesProvides central storage area

ClientsOther 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:LimewireBitTorrentGnutellaKazaa

Network Topologies

Layout of the computers and devices in a communications network.

Three most common:BusRingStar

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

Assignment

Create a Turkey-Gram-See instructions on calendar