Quick Summary
- A NIC (Network Interface Card) is the piece of hardware every device needs just to be able to connect to a network at all — wired or wireless.
- Every NIC is stamped with a MAC address at the factory — a permanent, unique "serial number" used for local traffic (LAN).
- An IP address is a location-based address (like a postal address) that can change depending on which network you're connected to — used for internet traffic (WAN).
- IPv4 uses 4 bytes (32 bits) written in denary; IPv6 uses 16 bytes (128 bits) written in hex — IPv6 exists because IPv4 was running out of addresses.
- A router is the device that connects your local network (LAN) to the wider internet (WAN), directs data packets, and hands out IP addresses.
1. Network Interface Card (NIC)
Think of a NIC like a passport. Without one, a device simply isn't allowed to "travel" onto a network — it has no way of sending or receiving anything. Every laptop, desktop, phone, printer or smart TV that connects to a network — whether by a cable or over Wi-Fi — has a NIC built in somewhere inside it, even if you never see it, because it's often built directly onto the motherboard rather than being a separate card you can pull out.
The exam board only really wants one core fact from you here, so let's make sure it's rock solid:
Key Definition
A Network Interface Card (NIC) is required for a computer to connect to a network. It can be wired (using a cable, e.g. Ethernet) or wireless (using Wi-Fi), and it allows a device to send and receive data over that network.
It's worth knowing that the NIC sits alongside other pieces of network hardware, even though the exam focuses on the NIC itself:
- Router — connects networks together (covered fully in Topic 3)
- Wireless Access Point (WAP) — lets wireless devices join a wired network
- Switch — forwards data to the correct device within a LAN, using MAC addresses
- Transmission media — the physical "roads" data travels on (cables or radio waves)
- NIC — the device's own "ticket" to get onto the network in the first place
Analogy
If a network is a road system, the NIC is like the car's licence plate holder and engine combined — without it, the car can't even get onto the road, let alone be identified once it's there. The MAC address (coming up next) is the actual licence plate itself.
Practice Question
Question 1
A smartphone can connect to a network without any visible cable or plug-in card. Explain why the smartphone still needs a NIC.
Question 2
State whether a NIC can be wired, wireless, or both.
2. MAC Addresses & IP Addresses
This is the part of the chapter that trips students up the most, mostly because MAC addresses and IP addresses sound similar and both look like a jumble of numbers and letters. But once you separate them by "where they're used" and "whether they change," it all clicks into place.
MAC Addresses
MAC (Media Access Control) address
local area network (LAN)
at the point of manufacture
static
switches
3. Router
router
Key Definition
router
routing data packets between different networks
wide area network (WAN)