140 likes | 149 Views
Learn about the different types of computer networks, including LAN and WAN, and explore various network topologies such as Line, Ring, Star, and Wireless. Compare stand-alone and networked computers and understand the advantages and disadvantages of each.
E N D
Networks Mr Hewitt
Objectives • By the end of this lesson you will be able to: • Compare stand alone, networked and laptop computers • Define a Network • Explain the terms LAN and WAN • Understand network topology
Types of computer CAN YOU GIVE A DEFINITION OF EACH? Stand alone PC Laptop PC Network A PC that is not connected to any other computer A lightweight portable computer A collection of computers linked together
What is a Network? What is a Network • ‘A collection of computers are linked together so they can communicate’ • ‘Networked computers can share hardware software and data’ Stand alone PC Network
What is a LAN • LAN stands for a ‘Local Area Network’ • The School network is a LAN • All computers are in the same building • Computers are permanently connected • Each computer is a workstation • There is a server with applications software, a list of users and passwords • Lans users need a password to log on
What are the advantages of LAN’s? • Shared software and peripherals e.g. printers • Workstations can be lower spec • Centralised information storage • Users can communicate & share data
What are the disadvantages of LAN’s? • Security is needed to protect programs • A network technician is needed • Faults can affect all users
What is a WAN? • WAN stands for Wide Area Network • Computers are spread over a large area • Computers are linked by phone lines radio or satellite links • The Internet is one big WAN • Computers are not permanently connected
What are the advantages of WAN’s • Ease of communication • Access to information • Work from home • Advertising and E-business
What are the disadvantages of a WAN? • Viruses - need firewall • Lack of face to face interaction • Costly • Risk of data being intercepted
Line or Bus Networks Good Points: Cheap – doesn’t use much cable All data is sent to and from the file server along a central line of cable. All terminals are connected to the central line Bad Points: Can be slow as all data goes down the central line If the central cable fails, the whole network goes down
Ring Networks Good Points Cheap to add computers Fast as data only flows one way Terminals are linked in a ring, data flows around the network in one direction only Bad Points The system gets slow when there are lots of users If the central cable fails the whole network goes down
Star Networks In a Star Network, a large number of computers are directly connected to the server Good Points If one computer or a cable fails, the others will be unaffected This is the fastest network Bad Points If the central computer fails, the whole network will go down Uses lots of cable so is expensive
Wireless Networks In a wireless network, there are no wires! The server will act as abase station which will be able to receive wireless transmission of data Computers have a wireless network card