🔌 Component 1 · 1.3 Computer Networks
1.3.1c Network Hardware (NIC, Switch, Router & WAP)
OCR J277 · GCSE Computer Science · ~11 min read
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Network Interface Card (NIC)

A Network Interface Card (NIC) is a hardware component that connects a device to a network. Every device that needs to connect to a network requires a NIC.

  • Wired NIC: connects via an Ethernet cable (RJ-45 port)
  • Wireless NIC: connects via Wi-Fi (radio waves)
  • Each NIC has a unique MAC address (Media Access Control address) — a 48-bit hardware address assigned at manufacture
  • Modern computers often have both wired and wireless NICs built in

Switch

A switch is a networking device used to connect multiple devices within a LAN. It receives data from one device and forwards it only to the intended device on the network.

  • Uses MAC addresses to identify which device is connected to which port
  • Maintains a MAC address table (also called a switching table)
  • More efficient than a hub — sends data only to the destination device, not to all devices
  • Operates at the Data Link layer of the OSI model
FeatureSwitchHub
Data forwardingOnly to destination deviceTo all connected devices
EfficiencyHighLow (creates unnecessary traffic)
SecurityBetterPoor (all devices see all data)
Used inModern networksLegacy/cheap networks

Router

A router connects different networks together and routes data packets between them. It connects your home/office LAN to the internet (WAN).

  • Uses IP addresses to route data to the correct destination across networks
  • Determines the best path for data packets to travel
  • Maintains a routing table — a list of known networks and best paths
  • Operates at the Network layer of the OSI model
  • Home routers often combine router, switch, and WAP in one device

Switch vs Router: A switch connects devices within a LAN using MAC addresses. A router connects different networks (e.g. LAN to internet) using IP addresses.

Wireless Access Point (WAP)

A Wireless Access Point (WAP) allows wireless devices to connect to a wired LAN. It broadcasts a Wi-Fi signal that devices can connect to.

  • Connected to a switch or router via an Ethernet cable
  • Extends the reach of a wired network to wireless devices
  • Used in offices, schools, and public spaces
  • Multiple WAPs can be installed to provide coverage across a large building

Summary of Network Hardware

DevicePurposeKey feature
NICConnects a device to a networkHas unique MAC address; wired or wireless
SwitchConnects devices within a LANUses MAC addresses; sends data only to destination
RouterConnects different networks; routes packetsUses IP addresses; connects LAN to internet
WAPAllows wireless devices to connect to a wired LANBroadcasts Wi-Fi; connected to switch/router via cable
Exam tip: Know all four devices (NIC, switch, router, WAP) and what each one does. The key distinction: a switch uses MAC addresses to send data to a specific device within a LAN; a router uses IP addresses to send data between different networks. Also know: a router at home connects your LAN to the internet. NIC = every device needs one to connect. WAP = needed for Wi-Fi access.
⚠️ Common Mistakes
  • Confusing a switch with a router — a switch connects devices WITHIN a network; a router connects BETWEEN networks
  • Saying a router uses MAC addresses — routers use IP addresses; switches use MAC addresses
  • Saying a WAP is the same as a router — a WAP only provides wireless access; a router routes data between networks
  • Forgetting that every device needs a NIC to connect to a network
  • Confusing a switch with a hub — a switch is intelligent (sends to destination only); a hub broadcasts to all
✅ Notes completed!
Video coming soon

What's in this video

  • • NIC — every device needs one; MAC address; wired/wireless
  • • Switch — MAC addresses, LAN only, sends to destination device only
  • • Router — IP addresses, connects networks, internet gateway
  • • WAP — wireless access to wired LAN, Wi-Fi broadcasts
Click slide or press arrow keys to navigate

Worksheet — 1.3.1c Network Hardware

8 questions · 21 marks

Q1What is a Network Interface Card (NIC)? What does each NIC have that makes it unique?[2]
✅ Mark scheme
A NIC is a hardware component that connects a device to a network [1]; each NIC has a unique MAC (Media Access Control) address assigned at manufacture [1].
Q2What is a switch and how does it differ from a hub?[3]
✅ Mark scheme
A switch connects devices within a LAN [1]; a switch uses MAC addresses to send data only to the intended device [1]; a hub broadcasts data to all connected devices, making it less efficient and less secure [1].
Q3Explain the role of a router in a network.[3]
✅ Mark scheme
A router connects different networks together [1]; it uses IP addresses to determine the best path for data packets to travel between networks [1]; it connects a home/office LAN to the internet (WAN) [1].
Q4State the difference between how a switch and a router forward data.[2]
✅ Mark scheme
A switch uses MAC addresses to forward data to a specific device within the same network (LAN) [1]; a router uses IP addresses to route data between different networks [1].
Q5What is a Wireless Access Point (WAP) and what is its purpose?[2]
✅ Mark scheme
A WAP is a device that allows wireless devices to connect to a wired LAN [1]; it broadcasts a Wi-Fi signal and is connected to the LAN via an Ethernet cable [1].
Q6A school wants to allow tablets to connect wirelessly to the existing wired LAN. Which device should be installed? Explain why.[2]
✅ Mark scheme
A Wireless Access Point (WAP) [1]; it broadcasts a Wi-Fi signal allowing wireless devices to connect to the existing wired LAN without needing a physical cable [1].
Q7Describe the purpose of a MAC address and explain how a switch uses it.[3]
✅ Mark scheme
A MAC address is a unique hardware identifier assigned to a NIC at manufacture [1]; a switch maintains a table of MAC addresses and the port each device is connected to [1]; when data arrives, the switch looks up the destination MAC address and sends the data only to that port/device [1].
Q8List the four main pieces of network hardware covered in this topic and briefly state the purpose of each.[4]
✅ Mark scheme
NIC — connects a device to a network [1]; Switch — connects devices within a LAN using MAC addresses [1]; Router — connects different networks using IP addresses; routes packets to internet [1]; WAP — allows wireless devices to connect to a wired LAN [1].
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Mini Test — 1.3.1c Network Hardware

10 questions · 10 marks · 10 minutes

← 1.3.1b Network Performance 1.3 Computer Networks 1.3.1d Network Topologies →
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