Computing

Computing

1. Networks

   • A network is when there are multiple computers connected together.
     • Advantages
       • It is easy to communicate using e-mail, etc.
       • It makes it easier to share software and devices, such as printers.
       • Files can be stored on one device and shared across many devices.
       • Information that is stored on the network can be accessed anywhere.
     • Disadvantages
       • The computers being linked means that it is easier to viruses to spread and damage the network.
       • Users that rely on the network might be stuck without it.
       • It Is easier for hackers to gain access to the network that it would be on a single computer.
       • Network hardware such as routers and network cards are needed to set up large networks and it might require a professional.
     • Data packets are how information is transmitted in a network.
     • LAN (Local Area Network): A network of computers within the same building, such as a school, a LAN is not necessarily connected to the internet.
     • WAN (Wide Area Network): They are created when LAN's are connected and require things such as broadband cables.
     • VPN (Virtual Private Network): They are usually set up on another network, like the internet and are used when working on secure information held by a company.
     • WPAN (Wireless Personal Area Network): A network comprised of personal devices such as smartphones and desktop computers.
       • If it has wires it is called a PAN.
     • Topology
       • Bus
         • A bus network Is when all the devices are connected with one cable with terminators at either end.
           • If the main cable fails, the entire network will fail.
           • It is easy and cheap to install.
       • Ring
         • A ring network is where all the devices are connected to two other devices in a ring.
         • Can transfer information quickly and there are never any collisions.
         • If the main cable or any of the devices fail the whole network will fail.
       • Star
         • In a star network, each device connects to a hub or switch in the middle.
           • No data collisions and if one device fails the rest can continue.
           • It is expensive to install due the cabling and extra hardware like hubs and switches are needed.
     • Wired
       • When computers are connected with Ethernet cables.
     • Wireless
       • Advantages
         • Can connect to multiple devices without extra hardware.
         • There is less disruption to the building as no wires are installed.
       • Disadvantages
         • More open to hacking.
         • Slower than wired networks and the connection is not as stable.
         • Interference may occur and it will loose quality through walls and other obstructions.