Networking Two or more computers linked together so that it is capable of sending messages between them. Network Stand Alone Computer

Local Area Network (LAN) Cover a small area such as a room or a building. Schools Office Buildings

Advantages Share data and programs between stations. Share peripherals, such as, printers, scanners. (Resource Sharing) other stations. Kept secure by use of passwords - Unauthorised interference can be reduced. Log on to any station on the network

Wide Area Network (WAN) A computer network that spans a relatively large geographical area. The Internet is the best-known example of a wide area network.

On-Line Connected to a network. Logging on to a file server. Off-Line Logging off of a network. Not connected to a network.

Cables and Wireless Cables There are two common types of cables used: 1.Unshielded Twisted pairs of copper wire(UTP) 2.Optical Fibre Cable Unshielded Twisted pairs (UTP) Copper wire carries electrical signals Optical Fibre Cable Very fine strands of glass that can transmit data very rapidly by using beams of light

Unshielded Twisted pairs (UTP) Advantage Cheap Disadvantage Interference can occur Can be tapped into Optical Fibre Cables Advantage Data is transmitted faster Does not corrode Disadvantage Expensive

Wireless A method or way of transmitting data without using a physical connection. E.g radio wave or infrared. Infrared Communication Bluetooth WiFi Microwave Transmisson Satellite Links

Infrared Communication Uses the same system as your TV remote. Used for short range communication. Sunlight can interface. Bluetooth This replaces infrared uses radio waves. Used for short range transmission. Mobile phones or PDA use bluetooth.

WiFi (Wireless Fidelity Alliance) Connect to the network using radio signals, and computers can be up to 100 feet or so apart. These are examples of LAN

Wide Area Networks Wide area networks use telecommunications links to transmit and receive data. Telecommunication links used in wide area networks include: Microwave Transmission Satellite Links Optical Fibre

Microwave Transmission Many public telephone services use this. Use dish aerials Satellite Links Operates over long distance. Used for public telephone service for links with overseas.

Network Security Network Manager - decides on each users access level for a network. He decides on usernames and passwords. Passwords A secret code that you would use to gain access to a computer. Must be changes regularly and should not be to easy. Encryption Putting data into a code or scrambling it to prevent it being seen.

Physical Methods Locking the computer room or the disks away. Using magnetic strip cards to enter a room. Finger print scanning (this is known as bioscrypt)

Setting up WiFi – Credit Wireless Network Interface Card Create a Hotspot (Wireless Access Point Router) A hotspot is a connection point for a WiFi network. It is a small box that is hardwired into the internet. There are many WiFi hotspots now available in public places like restaurants, hotels, airports.

Client and Server Client A client is usually a desktop computer. A client accesses the server for files, data and programs. Server A server device hosts files, databases, Web sites, or other applications. Server devices often feature higher-powered processors, more memory, and larger disk drives than clients. Server Clients

Types File server (School) Printer Server Web Server Database Server (multi access) Multi Access (2 Marks) Many users at the same time

Network Interface Card Allows a computer to connect to a network. Wireless Network Interface Card Allows a computer to connect to a wireless network. Most laptops come fitted with this card.

Multi Access Many users may be on-line to a computer system at the same time. Multi Access Systems: Airline Reservation Police National Computer Automated telling (cash machines) machines A client and server is also an example of a multi-access system.

Teleworking Work from home using a WAN. (connected to the internet) Advantages Do not have to travel to work which reduces pollution and congestion (traffic) Look after young family (save money on child care) Employers save money on office space Take breaks when you want

Laws Data Protection Act Protects data on a computer Copyright, Design and Patents Act Protects music, books and logos, movies Computer Misuse Act Hacking and Viruses