Hardware

• A Network Interface Card (NIC) is an internal piece of hardware that allows a device to connect to a network. These used to be separate cards, but nowadays they're built into the motherboard. NICs exist for both wired and wireless connections
• This is a NIC (Network Interface Card)

  
• Switches connect devices on a LAN. Switches receive data (in units called frames) from one device and transmit this data to the device on the network with the correct MAC address

  This is a typical switch with lots of ethernet ports

  
• Routers are responsible for transmitting data between networks - they're always connected to at least 2 different networks

  
• Routers have a crucial role on the internet, directing data (in units called packets) to their destination

  
• Routers are used in homes and offices to connect the LAN to the internet. Most home 'routers' are in fact a router, switch and WAP all in one
• Wired ethernet connections are fast and reliable
• Ethernet (wired) networks can use different types of ethernet cables to connect devices on a LAN
• The most common ethernet cables are CAT 5e and CAT6. they are 'twisted pair' cables, containing four pairs of copper wires which are twisted together to reduce internal interference

  
• Coaxial cables are made of a single copper wire surrounded by a plastic layer for insulation and a metallic mesh which provides shielding from outside interferences

  
• Firbe optic cables transmit data as light. They are high performance (and therefore expensive) cables - they don't suffer interference and can transmit over very large distances without loss of signal quality

  
• Wireless uses radio waves to transmit data
• Like mobile phones and TVs, wireless networks use radio waves to transmit data
• Wireless networks are more convenient than wired networks as you can move around while still being connected - they're also often cheaper as you need fewer wires
• Bluetooth and Wi-Fi are two common wireless technologies
• Bluetooth

  • Usually a direct connection between 2 devices so that data can be shared
  • Connection range varies, but mobile devices are typically 10 metres
  • Low bandwidth compared to Wi-Fi
  • Often used in mobile/wearable devices - smartphones/watched, headphones, etc.
• Wi-Fi

  • Can be used by multiple devices to connect a LAN at the same time
  • Connections have a range between 40 and 100 metres
  • High bandwidth compared to Bluetooth
  • Often used in the home - routers, desktops, laptops, smartphones, etc.
• To set up a Wi-Fi network, you need a Wireless Access Point (WAP) device. The WAP is basically a switch that allows devices to connect wirelessly
• To connect, devices need a wireless NIC. This is often built-in, but if not you can use a USB dongle. HDMI dongles are popular for TVs