Technology
21 explanations and counting.
What is biometric data?
Your fingerprint, face, voice, and even the way you walk are all unique to you. When technology collects and uses that information, it's called biometric data — and it's become central to both security and surveillance.
What is a neural network?
The AI systems behind face recognition, voice assistants, and ChatGPT are all built on neural networks — computer systems loosely inspired by the way brains work. Here's the idea.
How does a self-driving car work?
A self-driving car has no idea what a road "is" — it just processes enormous amounts of sensor data every second and makes decisions. Here's what's actually going on behind the windscreen.
What is DeepSeek?
In January 2025, a Chinese AI lab released a model that matched the best American AIs at a fraction of the cost. Stock markets shook. Here's what DeepSeek actually is and why it mattered.
How does a large language model work?
ChatGPT and tools like it can write essays, answer questions, and hold conversations. But there's no mind inside — just an extraordinarily clever pattern-matching machine trained on almost everything humans have ever written.
What is quantum computing?
Regular computers have been getting faster for 60 years. Quantum computers work on completely different principles — and for certain problems, they'd make today's fastest computers look like a pocket calculator.
How does facial recognition work?
Your phone unlocks by looking at your face. Police use it to identify suspects in crowds. Here's the technology behind it — and why it's so controversial.
How does social media work?
Billions of people use it every day. But what's the actual business model, and why are the apps designed the way they are?
How do batteries work?
A battery is basically a controlled chemical reaction in a can — turning stored chemical energy into electricity on demand.
What is virtual reality?
Strap on a headset and step into a different world entirely. Here's how VR tricks your brain into believing it's somewhere it isn't.
What is coding?
Every app, website, and piece of software was built by someone writing instructions in a language computers can follow. Here's what that actually involves.
What is an algorithm?
Algorithms decide what you see on social media, who gets a loan, and what music gets recommended to you. Here's what they actually are.
How does encryption work?
Every time you buy something online, your card details travel across the internet scrambled in a code so complex that no computer on Earth could crack it. Here's how.
What is "the cloud"?
Your photos, documents, and music live "in the cloud." But where is the cloud, actually? It's more concrete — and more interesting — than the name suggests.
How do touchscreens work?
You press your finger on glass and a machine responds. The invisible technology that makes this work is stranger than it looks.
How does GPS work?
Your phone knows exactly where you are on Earth to within a few metres, at all times. Here's the elegant maths that makes it possible.
How do search engines work?
You type a question and get a million answers in 0.4 seconds. The system behind that is one of the most complex ever built.
What is a computer virus?
Computer viruses are named after biological ones for a very good reason. Here's how malicious software works and why it spreads.
What is artificial intelligence?
AI can write essays, recognise your face, beat world champions at chess, and recommend your next favourite song. What's actually going on inside it?
How does the internet work?
You use it constantly, but the internet is a genuinely mind-bending engineering achievement. Here's how data gets from anywhere to your screen.
How does Wi-Fi work?
How does the internet get from a box in your hallway to your phone without any wires? It's basically invisible radio.