Behind the scenes
2:03How are web animations turned into videos?
A scene is a function of time: Chromium captures it frame by frame, ffmpeg encodes the video and mixes in the narration.
2:23How does a browser render a page?
From HTML and CSS bytes to pixels: DOM, CSSOM, render tree, layout, paint and compositing.
2:40From typing a URL to seeing the page
DNS, TCP and TLS, a static frontend served from a CDN, one call to a Go API, and the final render.
Grade 9 · Unit 2: Data transmission
1:32Data packets and packet switching
Packet structure, routing, out-of-order arrival and reassembly.
1:19Simplex, half-duplex and full-duplex
Which way the data flows, and when.
1:43Serial and parallel transmission
Bits one by one or all at once, skew, crosstalk and USB.
1:21Error detection
Why errors happen, and checksums, echo checks and ARQ.
1:13Parity checks
Parity bits and parity blocks, including finding and fixing a flipped bit.
1:32Check digits
The multiply, add, divide-by-10 method with a worked example and a practice question.
1:28Encryption
Eavesdroppers, symmetric keys and the public and private key pair.
5:08Unit 2 quiz
Ten questions with a think-time countdown and explained answers.
How AI works
1:14How does AI work?
Neurons and weights, learning from mistakes, and predicting the next word.
1:13How does AI read a sentence?
Tokens, embeddings and attention, stacked in layers to score the next token.
1:17What are billions of parameters?
What a parameter is, how big a billion is, and why big models need racks of GPUs.
1:26How do networks learn from errors?
Loss as a landscape, gradient descent and backpropagation.
1:24How is a chatbot trained?
Pretraining, fine-tuning and human feedback turn a text predictor into an assistant.
1:23What does temperature do?
Scores become probabilities, and temperature sharpens or flattens them.
1:19How does AI draw pictures?
Diffusion models add noise to learn, then remove it to create, steered by a prompt.
1:15How can AI use your own documents?
Retrieval-augmented generation: embed, retrieve, augment the prompt, generate.
1:14Why does AI make things up?
Likely is not the same as true: gaps, snowballing errors, and what helps.
1:16How much can an AI remember?
The context window, forgetting, the cost of long inputs, and workarounds.
1:09What is an AI agent?
A model in a loop with tools and guardrails.
1:12Can AI be biased?
Skewed data, where bias comes from, proxies, and how to audit and fix it.
1:10What is overfitting?
Underfit, good fit and overfit curves, train vs test error, and the fixes.