These two get confused constantly, and confusing them costs marks. Think of a pipe: bandwidth is how wide it is, latency is how long it is.
The same pipe drawn two ways, then the rules both ends agree on.
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A protocol is an agreed set of rules for how two machines talk: how to start, how to send, how to say something went wrong. Standards are protocols everyone has agreed to use.
- TCP/IP
- The pair that makes the internet work: IP finds the destination, TCP makes sure everything arrived.
- HTTP and HTTPS
- How a browser asks for a page. The S means the conversation is encrypted.
- Wi-Fi standards
- Why a laptop made by one company works with a router made by another.
Why open standards matter: Because the rules are public, anybody can build equipment that joins the network. That is why no single company owns the internet — and it was a decision, not an accident.
Standards make networks work together
Interoperability
Devices from different makers work together because they follow the same standards.
Addresses
Every device online has an IP address, a number that says where to deliver data.
Domain names
Names such as wikipedia.org that people can remember; the Domain Name System turns them into IP addresses.
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Networks are built to route around damage: if one path fails, traffic takes another. That makes them hard to break by accident — and hard to shut down on purpose.
Hard to break
- One cable cut rarely takes a country offline
- Traffic re-routes automatically
- Services stay up through local failures
Hard to control
- Censorship is difficult to enforce completely
- Blocked material reappears through another path
- Shutting it down means ordering the operators, not cutting a wire
Network security, layer by layer
Identification
Saying who you are: a username.
Authentication
Proving it: a password, a fingerprint, a code sent to your phone.
Encryption
Scrambles data in transit so an eavesdropper cannot read it.
Firewall
Checks traffic at the edge of a network and blocks what breaks its rules.
Proxy server
Stands between users and the internet, hiding their addresses and filtering requests.
VPN
An encrypted tunnel across the internet to a trusted network.
Capacity and infrastructure
Security layers
No single defence is enough, so several are stacked: if one fails, the next still stands.
Data compression
Makes files smaller so they use less bandwidth: a streamed film is heavily compressed.
Net neutrality
The principle that providers treat all traffic equally, not speeding up the services that pay them.
Internet backbone
The high-capacity fibre links, including undersea cables, that carry traffic between countries.
Real-world examples you can name
The Colonial Pipeline ransomware attack — May 2021
A ransomware group reached the company's network through a single reused password on an old VPN account. The company shut the pipeline down for several days as a precaution, causing fuel shortages along the US east coast, and paid a ransom of which US authorities later recovered part.
Who it affected: Drivers and airports across the eastern United States.
Government internet shutdowns — tracked annually by Access Now since 2016
States order operators to suspend mobile data or the whole internet, usually during protests, elections or exams. India has recorded the most shutdowns of any country for several consecutive years.
Who it affected: Everyone in the affected region — including businesses, hospitals and students.
How this is tested — you have to use bandwidth, latency and protocol precisely and explain a described problem with the right one. It comes up two ways:
Paper 1 — structured question
- Part a: identify characteristics of a network
- Part b: explain why a described service performs badly
Paper 2 — source-based question
- Q1: read a speed or delay figure off a source
- Q2: explain a technical claim a source makes
The trap: calling everything “speed”: A video call that stutters is usually a latency problem. A download that crawls is usually bandwidth. Saying “slow internet” answers neither.
Distinguish between bandwidth and latency.
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Explain two ways a school could manage limited bandwidth during the school day.
Model answer plan
See the answer broken into clear points, with guidance on how each point earns marks.