Network Hardware and Standards
Why Network Hardware Matters
Every network is built from physical components that move data between devices. Understanding what each piece of hardware does — and why it differs from the others — is essential for your exam. You need to know six devices: router, hub, switch, bridge, wireless access point (WAP) and network interface card (NIC).
Routers
A router connects different networks together and directs data packets between them. When you type a web address at home, your router decides the best path for your request to take across the internet. Routers operate at the Network layer of the OSI model, reading IP addresses to make forwarding decisions.
Most home routers also include a switch, a wireless access point and a modem all in one device, but in larger business networks these functions are handled by separate pieces of hardware.
Switches
A switch connects multiple devices within a single network — for example, all the computers in one classroom. Unlike a hub, a switch is intelligent: it maintains a table of MAC addresses so it can send data directly to the correct device rather than broadcasting it to everyone. This makes switches far more efficient than hubs and is why they are standard in modern networks.
Hubs
A hub also connects multiple devices, but it has no intelligence. When a device sends data to the hub, the hub broadcasts it to every other connected device. The intended recipient reads it; all other devices discard it. This wastes bandwidth and creates security risks because any device can “hear” all traffic. Hubs have been almost entirely replaced by switches in real networks.
A switch uses a MAC address table to deliver data only to the correct destination device. A hub broadcasts data to every connected device. This is why switches are more efficient and more secure than hubs.
Bridges
A bridge connects two separate network segments and decides whether to forward or block data based on MAC addresses. If a frame is destined for a device on the same segment it came from, the bridge drops it; if it is destined for the other segment, the bridge forwards it. Bridges reduce unnecessary traffic crossing between segments and can connect different media types (for example, copper and fibre).
Bridges are similar to switches but operate between two segments rather than many ports. In modern networks, switches have largely replaced standalone bridges.
Wireless Access Points (WAPs)
A wireless access point (WAP) allows devices such as laptops, smartphones and tablets to join a wired network without a physical cable. The WAP translates between the wireless (Wi-Fi) and wired (Ethernet) protocols. In a large building such as a school, multiple WAPs are placed throughout to give full coverage, all connected back to the same wired network infrastructure.
Network Interface Cards (NICs)
A network interface card (NIC) is the hardware component inside every networked device — computer, printer, smart TV — that handles the connection to the network. Each NIC is assigned a globally unique MAC address at manufacture. This 48-bit address is used by switches and bridges to identify devices. Modern devices have both a wired NIC (Ethernet port) and a wireless NIC (Wi-Fi) built in.
The six network hardware components you must know are: router (connects networks, uses IP addresses), switch (connects devices in a network, uses MAC addresses), hub (broadcasts to all devices), bridge (joins two segments, filters by MAC), WAP (wireless to wired connection) and NIC (the hardware interface inside every device, with a unique MAC address).
Networks carry data over physical media (wired) or radio waves (wireless). Both have trade-offs that you may be asked to compare.
Wired (Ethernet) uses copper or fibre-optic cables to transmit data. Copper is cheaper but limited in speed and distance; fibre-optic uses pulses of light and offers much higher bandwidth over longer distances but is more expensive to install. Wired connections are more secure (a physical cable cannot easily be intercepted) and more reliable (no interference from walls or other devices).
Wireless (Wi-Fi) uses radio waves, allowing devices to connect without cables. This gives flexibility — users can move around while staying connected. However, wireless signals can be blocked by walls, interfered with by other devices using the same frequency, and intercepted more easily than a wired connection, creating security risks. Speed and range decrease with distance from the WAP.
A networking standard is an agreed set of rules that ensures devices from different manufacturers can communicate reliably. Without standards, a router from one company might not be able to talk to a switch from another.
The most important networking standards you need to know are:
- IEEE 802.3 (Ethernet) — defines how devices connect over wired cables and how they take turns to transmit data.
- IEEE 802.11 (Wi-Fi) — defines how wireless devices communicate using radio frequencies. The 802.11 family includes amendments for different speeds and frequencies (for example, 802.11ac operates on 5 GHz and supports speeds above 1 Gbps).
Standards are developed by international bodies such as the IEEE (Institute of Electrical and Electronics Engineers) so that manufacturers worldwide follow the same rules. This means you can buy any Wi-Fi router and connect any Wi-Fi-certified device to it, regardless of manufacturer.