ICT Form 2 Notes Theory

• Network Interface Cards (NIC)


  Allow an electronic device to be connected to a network and has a unique media access control address (MAC address)
• Hubs


  • Allow several devices to be connected to them
  • Data packets sent to every device on the network
  • Creates unnecessary traffic and security issues
• Switches


  • Connect several devices, only send data to intended device
  • Have a lookup table to match MAC addresses to ports
• Bridges


  • Connect two networks or network segments to create a single larger network
  • Cannot communicate with external networks
• Bluetooth


  Wireless communication technology, allows devices to connect within a 30m range
• WiFi


  Wireless communication technology, allows devices to connect up to 100m range, devices connect to a hotspot or wireless access point
• Cloud computing


  Data is stored on remote servers and accessed through the internet
• Types of cloud storage

  • Public Cloud
  • Private Cloud
  • Hybrid Cloud
• Advantages of cloud computing

  • Cheap
  • Easily accessible
• Disadvantages of cloud computing

  • Needs good internet
  • Not secure
  • Costly
• Internet


  Very large global network of interconnected networks, World Wide Web is the collection of web pages accessible through the internet
• Characteristics of the internet


  • Open
  • Global reach
  • Accessible
• Intranet


  Private network used to send information securely within an organisation, access is restricted to authorised users
• Advantages of intranet


  • Data kept within the organisation
  • Less chance of hacking and attacks
  • Administrators can manage access
• Extranet


  Private intranet that also allows access by selected external parties, with authorisation levels determining access
• LAN (Local Area Network)


  Networks contained within a single building or small geographical location, made up of hubs and/or switches connected to a router
• Advantages of LAN


  • Security
  • File sharing and collaboration
• Disadvantages of LAN


  • Hardware failure affects network
  • Not secure
  • Slow
• WAN (Wide Area Network)

  Wireless LANs (WLANs) allow wireless device connection using wireless access points
• Advantages of WLAN


  • Mobility
  • Flexibility
  • Wireless device access to peripherals
• Disadvantages of WLAN


  • Bandwidth issues in high traffic
  • Interference from other devices
  • Security vulnerabilities
• Data interception


  Unauthorised user intercepting data being transferred
• Passwords


  Common security measures that should be changed regularly and use a combination of characters that dont contain personal information
• Authentication


  Zero login methods like biometrics and behavioural patterns
• Magnetic stripe cards


  Store user data on a magnetic stripe, scanned through a reader for authentication, can be easily cloned
• Smart cards


  Contain a chip with personal identification information, can only be read by authorised devices, more secure than magnetic stripe
• Physical tokens


  Small physical device that generates one-time passwords for authentication, can be disconnected or connected to the system
• Anti-malware


  Software designed to detect, prevent and remove malicious software
• Backing up data


  Copying files or data to a different medium to prevent loss or damage of original
• Magnetic tape drives


  Used for batch processing and long-term data archiving, fast data transfer but slow access times, affected by magnetic fields
• Fixed hard disks/drives


  Stores applications and files and can be easily damaged and noisy
• Portable hard disk drives

  Can be used for backup and data transfer between computers, fast data access and transfer but can be easily damaged
• Optical media and optical storage devices

  Store data by burning 'dots' onto the surface with a laser, data read by lower-powered laser
• Blu-ray discs


  Use blue laser instead of red, have secure encryption, faster data transfer than DVDs, used for storing and playing movies and storing data on computers
• Advantages of Blu-ray


  • Very large storage capacity
  • Very fast data transfer rate
  • Plays and stores movies
• Disadvantages of Blu-ray


  • Expensive
  • Encryption problems
• Solid State Drives (SSD)


  Storage device with no moving parts, more reliable, lighter and lower power consumption, but smaller capacity compared to hard drives