Ict Revision

• Network


  An interconnection of two or more computers to share resources such as printers, software, data, and files
• Types of networks


  • Wired (connected with cables)
  • Wireless (using a router and Wi-Fi)
• Internet


  The largest network, where information can be accessed from any part of the world
• Uses of networks

  • File sharing
  • Printer sharing
  • Data sharing
  • Sharing other resources
• Advantages of using networked computers:
• Disadvantages of using networked computers:
• Network Interface Card (NIC)


  Allows a device to connect to a network by converting data to electrical signals
• MAC address


  A 48-bit number that uniquely identifies a device on a network
• IP address


  A unique code assigned to a device by an internet service provider, identifies the location of the device on a network
• Data packet


  Data sent from a sender to a receiver, broken down into small parts with a header containing sender/receiver IP, sequence, size, and number of packets
• Hub


  A hardware device that allows devices to connect to form a local area network, but transmits data to all devices rather than just the intended recipient
• Switch


  A smarter version of a hub that stores MAC addresses in a lookup table to send data packets only to the intended recipient device
• Bridge


  A device used to connect two local area networks with the same communication protocols
• Router


  A device that joins local area networks to the internet, has its own IP address to send and receive data packets between network devices based on their IP addresses
• Bridge


  A device used to connect two local area networks together that have the same communication protocols
• Communication protocols


  Communication rules
• Router


  • Connects a network to the internet
  • Stores IP addresses of devices in its network
  • Uses a routing table to send data packets to the correct destination
• IP address


  Enables a router to send and receive data packets between different network devices
• How a router works

  1. Inspects data packet to determine destination IP address

  2. Sends data packet to local hub or transmits to another network to reach correct destination
• Every device connected to the internet has an assigned IP address
• Web page


  Has a unique IP address and domain name, stored on a web server
• Someone sends data online

  The data is transmitted through connected networks to the destination
• Routers only store IP addresses, not MAC addresses
• Router receives data


  Sends it to local switch, which redirects it to the destination device
• Bridge


  Connects networks using the same communication protocols
• Router


  Connects networks with different communication protocols, uses IP addresses and routing table
• Switch


  • Allows many computers to be connected
  • Stores MAC addresses of connected devices
  • Directs data to specific devices using MAC addresses
• Wireless network (Wi-Fi)


  Allows wireless communication between devices using electromagnetic radiation
• Wi-Fi networks


  • Operate at full scale
  • Offer fast data transfer
  • Provide security
  • Allow file transfer up to 100m apart
• Bluetooth


  • Allows wireless communication between devices in close proximity (decimeters)
  • Offers slow data transfer
  • Has low bandwidth
  • Uses encryption for secure personal area network
• Cloud computing


  Storing and accessing data on remote servers over the internet
• Cloud storage systems


  • Public cloud
  • Private cloud
  • Hybrid cloud
• Public cloud


  Storage environment where the client and storage provider are different companies
• Private cloud


  Storage environment where the client and storage provider are the same entity
• Hybrid cloud


  Combination of public and private cloud storage, with sensitive data in private cloud and public data in public cloud
• Local area network (LAN)


  Small network covering a small geographic area
• Wireless LAN


  LAN using wireless communication
• Wide area network (WAN)


  Network covering a large geographic area
• For the company, there was a technical problem and a shutdown, so the client will now be able to access their data if they have a slow data connection accessing the cloud storage can be difficult
• Accessing the cloud storage can be difficult if the client has a slow data connection